Satcom and Vessel Tracking: How Ships Connect

A ship that clears the breakwater used to drop off the edge of the connected world. For most of the twentieth century a master mid-ocean had a HF radio that crackled, a telex that ran at a few hundred bits per second, and not much else, and the shore knew where the ship was only when it chose to report. That has reversed. A modern merchant ship carries two distinct radio systems that answer two distinct questions: how does it call for help, and how does anyone know where it is. The first is the Global Maritime Distress and Safety System (GMDSS) under SOLAS Chapter IV; the second is the pair of tracking systems, AIS and LRIT, under SOLAS Chapter V. Layered over both is a commercial satcom fit that has gone from a 64 kbit/s L-band channel to a low-Earth-orbit broadband link in under a decade. This article is the hub for the satellite communication and tracking cluster: it sets out the safety system, the tracking systems, and the connectivity that now carries the operational and welfare traffic, then routes to the polar-communications calculators that put numbers on the satellite-and-radio fit.

The logic of the cluster is one question asked three ways. A ship has to be able to raise the alarm from anywhere it legally trades; it has to be locatable by the authorities that have a stake in it; and it increasingly has to move large volumes of operational and crew data to and from shore. GMDSS answers the first, AIS and LRIT answer the second, and the VSAT-and-LEO satcom fit answers the third. The same hardware, an antenna pointed at a satellite, increasingly serves all three, which is why the safety, security, and commercial layers can no longer be treated as separate boxes on the mast. The four cluster calculators sit on the polar end of the problem, where the choice between HF, Inmarsat, and Iridium is sharpest: the polar communications backup calculator, the polar HF DSC communications calculator, the polar Inmarsat A3 communications calculator, and the polar Iridium A4 communications calculator.

GMDSS: the distress and safety system

The Global Maritime Distress and Safety System is the framework that decides what radio equipment a ship must carry so that a distress alert reaches a rescue coordination center from wherever the ship is, treated equipment-first in the GMDSS overview. It is set out in SOLAS Chapter IV, adopted in 1988 and in force from 1 February 1992, and it replaced the old manual Morse-watch system with an automated, satellite-and-terrestrial scheme. The governing idea is that the alert should be automatic and should reach shore even if the crew has seconds, not minutes, so distress alerting runs on digital selective calling (DSC) over the terrestrial bands and on satellite over the oceans, backed by the EPIRB that floats free and transmits on its own.

GMDSS does not require every ship to carry every system. It requires the ship to carry the equipment that matches the sea areas it trades in, and those sea areas are defined by radio coverage, not by distance lines on a chart. This is the single most important concept in the system and the one most often stated loosely. The four areas are cumulative: a ship that trades in sea area A3 also carries the A1 and A2 equipment, because its voyages pass through A1 and A2 water near the coast on the way out and back.

The areas are not fixed coordinates: they depend on where coast stations and satellite footprints actually reach. Sea area A1 exists only where a national authority operates a VHF DSC coast station, so a stretch of remote coast with no such station has no A1 at all, and the next area out begins at the shoreline. Sea area A3 is bounded by the footprint of the recognized satellite service the ship carries, which is the detail that the 2024 modernization changed most.

The 2024 GMDSS modernization, adopted as IMO resolution MSC.496(105) and in force from 1 January 2024, rewrote SOLAS Chapter IV to remove obsolete equipment requirements and to open the satellite layer to more than one provider. The most consequential edit is linguistic: every reference to “Inmarsat” in the chapter was replaced with the neutral term “recognized mobile satellite service” (RMSS), because Inmarsat is no longer the only such service. The modernization also dropped the narrow-band direct-printing (NBDP) telegraphy requirement, moved the SART, AIS-SART, and two-way VHF survival-craft radios into Chapter IV, and tightened the EPIRB rules so a float-free satellite EPIRB is required in sea area A1 rather than a VHF EPIRB. The system’s spine, distress alerting matched to sea area, did not change; the equipment list inside that spine did.

The nine GMDSS functions and the equipment that delivers them

SOLAS regulation IV/4 frames the whole system not as a list of boxes but as nine functions every ship must be able to perform, and the carriage rules then say which boxes deliver those functions in each sea area. The nine functions are:

1. Transmit a ship-to-shore distress alert by at least two separate means.
2. Receive shore-to-ship distress alerts.
3. Transmit and receive ship-to-ship distress alerts.
4. Transmit and receive search-and-rescue coordinating communications.
5. Transmit and receive on-scene communications.
6. Transmit and receive locating signals.
7. Receive maritime safety information (MSI).
8. Transmit and receive general radiocommunications to and from shore.
9. Transmit and receive bridge-to-bridge communications.

The “at least two separate means” rule is the redundancy principle that drives the equipment count: a single failure must not silence the ship, so an A3 ship carries both a satellite ship earth station and an HF or MF DSC set, plus the float-free EPIRB as an independent third route.

The EPIRB is the float-free heart of the alert. A 406 MHz emergency position-indicating radio beacon, when a ship founders, releases from its hydrostatic bracket, floats clear, and transmits a coded distress message with the ship’s identity and, from its built-in GNSS receiver, its position to the Cospas-Sarsat satellite system, which relays it to the nearest rescue coordination center. Cospas-Sarsat is the international satellite search-and-rescue program, and its move to the medium-Earth-orbit MEOSAR payloads carried on GNSS satellites has cut detection-and-location time from the old low-Earth-orbit pass-wait to near real time. The EPIRB matters because it is the one piece of the GMDSS fit that works after the crew has abandoned the bridge: no human action launches it.

Maritime safety information is the receive side of the same system. NAVTEX, the international direct-printing service on 518 kHz, delivers navigational and meteorological warnings and urgent safety messages out to roughly 200 to 400 nautical miles of a coast station, and beyond NAVTEX range the SafetyNET service over the recognized satellite link carries the same MSI plus the search-and-rescue coordination traffic. A ship must be able to receive MSI for the entire voyage, which is why the satellite MSI receiver becomes mandatory once a ship leaves NAVTEX coverage. The search-and-rescue locating signals, the 9 GHz radar SART that paints a line of blips on a searching ship’s radar, and the AIS-SART that puts a marked target on the AIS display, are the on-scene homing aids that bring a rescuer the last few miles to a liferaft.

A worked sea-area fit-out

The carriage logic is clearest worked through a real route. Take a 25,000 GT bulk carrier loading grain in the US Gulf for discharge in Rotterdam, an Atlantic crossing that stays between 25 and 52 degrees north. The voyage runs through A1 water leaving the Mississippi and entering the approaches to Rotterdam, A2 water along both coasts, and A3 water across the ocean middle, but it never goes above 70 degrees, so it sees no A4. The required fit is therefore the A3 set: a VHF radio with DSC for the A1 legs and bridge-to-bridge, an MF/HF radio with DSC for the A2 legs and as the second alerting means offshore, a recognized satellite ship earth station for the A3 ocean crossing and the MSI, a NAVTEX receiver for coastal MSI, a float-free satellite EPIRB, and the survival-craft SART and two-way VHF radios. Now reroute the same ship to carry ore from Murmansk to a Chinese port over the Northern Sea Route, and the picture changes: the high-latitude legs cross into A4 water above 70 degrees north where an Inmarsat geostationary terminal cannot point, so either the ship carries a full HF DSC capability as its A4 alerting means or it fits an Iridium GMDSS terminal whose polar-orbit constellation covers the route end to end. That single change of trade, not a change of ship, is what flips a vessel from an A3 to an A4 fit, and it is exactly the decision the polar Iridium A4 communications calculator and the polar HF DSC communications calculator frame against each other.

Inmarsat, Iridium, and the recognized satellite services

For most of GMDSS history one company carried the satellite leg. Inmarsat, founded in 1979 as an intergovernmental organization and later privatized, ran the geostationary L-band constellation that defined sea area A3, and an Inmarsat ship earth station was the only satellite route to a rescue coordination center that SOLAS recognized. The geostationary orbit is the constraint that draws the A3 boundary: three or four satellites parked over the equator cover the globe between roughly 70 degrees north and 70 degrees south, but the look angle to a geostationary satellite drops to the horizon and below as a ship goes higher in latitude, so the poles fall outside Inmarsat’s GMDSS footprint. That gap is sea area A4, and it is why a ship trading into the Arctic or Antarctic carries HF.

Iridium changed the map. Its constellation of 66 active low-Earth-orbit satellites in near-polar orbits covers the entire surface, poles included, so an Iridium link works where a geostationary one cannot point. The IMO Maritime Safety Committee recognized Iridium for GMDSS by resolution MSC.451(99) in May 2018; the International Mobile Satellite Organization signed the Letter of Compliance in December 2019, and the Iridium GMDSS Safety Voice and short-burst data service went live in December 2020. An Iridium GMDSS ship therefore has satellite distress alerting in the polar regions that an Inmarsat-only ship does not, which collapses what would be sea area A4 for the Inmarsat ship into satellite-covered water for the Iridium ship. The polar-communications calculators in this cluster exist precisely because that choice, HF backup versus Inmarsat A3 reach versus Iridium A4 global cover, is the live decision for any operator routing through high latitudes, and the polar communications backup calculator frames the redundancy a polar voyage needs.

The practical upshot for a fit-out is that “recognized mobile satellite service” now means a choice. A ship can satisfy the A3 (and, with Iridium, effectively the A4) satellite carriage requirement with either provider, and the regulation no longer names one. What the regulation still demands is that the satellite distress function is independent, continuously available, and connects to a recognized rescue network, which is why the GMDSS satellite terminal is a regulated, type-approved unit distinct from the broadband terminal a ship uses for everything else.

The satcom landscape: L-band, VSAT, and the LEO shift

GMDSS handles the distress kilobit. The operational and welfare traffic, the noon report, the engine telemetry, the electronic charts update, the crew’s video call home, runs on a separate commercial satcom fit that has changed faster than any other system on the ship. Three layers coexist on a modern bridge and deckhouse, and they trade off coverage, bandwidth, and cost against each other.

L-band is the legacy workhorse and the safety anchor. Inmarsat’s FleetBroadband, running in the 1.5 to 1.6 GHz L-band, delivers up to about 432 kbit/s on a compact, always-available antenna that holds the link through heavy weather and steep roll, because the long wavelength is forgiving of antenna pointing and rain. That reliability is why L-band, not the higher-bandwidth bands, carries the safety and the guaranteed-availability traffic: the bandwidth is modest but the link almost never drops. FleetBroadband and the GMDSS terminal often share the L-band fit, which is part of why L-band survives even as the bulk data moves elsewhere.

VSAT (very small aperture terminal) in the Ku-band (around 12 to 14 GHz) and the Ka-band (around 20 to 30 GHz) brought the megabit. A stabilized VSAT antenna on a gyro-stabilized mount tracks a geostationary satellite through the ship’s motion and delivers committed information rates from a few megabits to tens of megabits per second, enough for real-time operational data, remote IT support, and a usable crew internet. The trade-off is rain fade: the higher the band, the more a heavy tropical downpour attenuates the signal, so Ka-band gives more raw throughput but loses more of it in bad weather than Ku-band does. VSAT made the connected ship commercially normal through the 2010s, but its geostationary architecture imposes a latency floor of around 500 to 600 milliseconds round trip, because the signal travels roughly 36,000 kilometers up and the same distance back.

The LEO shift broke that floor. Low-Earth-orbit broadband, Starlink from about 2022 on merchant ships and OneWeb behind it, puts the satellite a few hundred kilometers up instead of 36,000, which cuts latency to tens of milliseconds and raises throughput to hundreds of megabits per second at a fraction of the per-gigabyte cost of VSAT. That step change is what makes continuous engine-data streaming, remote diagnostics, and real-time shore support practical, and it is the technical enabler behind smart shipping and autonomy. The important regulatory point is the one operators most often blur: Starlink is not, as of 2026, a recognized mobile satellite service for GMDSS, so it cannot satisfy the SOLAS Chapter IV distress carriage. The mainstream fit in 2026 is therefore a LEO terminal for the bulk data and crew welfare, an L-band terminal for guaranteed-availability operational traffic, and a recognized GMDSS terminal (Inmarsat or Iridium) for distress and safety. Antenna real estate, airtime contracts, and the failover logic between the three are now a real naval-architecture and procurement problem, not an afterthought.

The band, the orbit, and the price move together, and the table makes the trade-off explicit. The pattern to read out of it is that no single layer wins on every axis: L-band trades bandwidth for availability, geostationary VSAT trades latency for a fixed footprint, and LEO wins on bandwidth and latency but is, for now, a commercial service with no safety mandate behind it.

The airtime side is its own decision. L-band is sold by the megabyte at a price that makes it a metered, last-resort pipe; VSAT is sold as a committed-information-rate contract with a monthly floor; LEO is sold as a high-cap or unmetered plan that finally makes streaming and crew internet affordable. The failover logic that ties them together, which traffic drops to which link when the primary fails and how the GMDSS terminal stays isolated from the rest, is set in the ship’s communication plan, and it is the part most often left underspecified until the first ocean crossing exposes a gap.

AIS: the open broadcast under SOLAS V/19

The automatic identification system is the ship’s continuous self-announcement, covered as bridge equipment alongside the electronic chart in AIS and ECDIS. An AIS transponder broadcasts the ship’s identity, position, course, speed, and voyage data on two dedicated VHF channels (161.975 and 162.025 MHz, channels 87B and 88B) several times a minute, and every other AIS-equipped ship and every shore station in range receives it. AIS is mandated by SOLAS regulation V/19, which requires it on all ships of 300 gross tonnage and upwards on international voyages, cargo ships of 500 gross tonnage and upwards not on international voyages, and all passenger ships regardless of size; the carriage requirement was phased in and became effective for all such ships by 31 December 2004. The technical standard behind the air interface is ITU-R Recommendation M.1371, and the performance standard is IMO resolution MSC.74(69) annex 3.

The distinction between Class A and Class B is the one that matters operationally, and it is set by the access scheme and the power. Class A is the SOLAS-grade unit: it transmits at 12.5 watts using SOTDMA (self-organizing time-division multiple access), in which each station reserves time slots so the broadcast is deterministic and does not collide, and it reports every 2 to 10 seconds when underway, faster when turning, and every 3 minutes at anchor. Class B is the lighter unit for vessels below the SOLAS threshold: the common CSTDMA version transmits at 2 watts, listens for a free slot before transmitting (so it yields to Class A under load), and reports roughly every 30 seconds. Class A also carries the fuller message set, including navigational status, rate of turn, and detailed voyage and destination data, where Class B sends a reduced set.

AIS was designed as a terrestrial VHF system, so its native range is line-of-sight, roughly 20 to 40 nautical miles ship to ship and more from a tall coast station. Satellite-AIS (S-AIS) extends it: receivers on low-Earth-orbit satellites pick up the same VHF broadcasts from orbit and give near-global coverage of the open ocean, which is how commercial tracking services follow ships mid-Pacific. S-AIS has a structural limitation: a single satellite footprint covers a huge ocean area in which thousands of Class A SOTDMA slots overlap and collide at the receiver, so detection in busy areas is probabilistic and a given ship may be missed on a pass. The system was built for local collision avoidance, and reading it as a complete global track requires care.

The deeper limitation is that AIS has no authentication. The message carries whatever the transponder is told to send, with no cryptographic check, so a ship can transmit a false position, broadcast another vessel’s MMSI, or simply switch off and go dark. This is not theoretical: vessels in sanctions-evading trades have been documented transmitting AIS positions that conflict with their satellite-AIS and radar tracks, and “dark” gaps where a tanker disables AIS for a ship-to-ship transfer are a routine compliance flag. Authorities counter it by cross-referencing AIS against S-AIS coverage gaps, coastal radar, optical and radar satellite imagery, and the closed LRIT feed, but the open AIS message set itself, defined in ITU-R M.1371, has no integrity protection. Spoofing detection and the move toward an authenticated successor (VDES, the VHF data exchange system, layered on AIS) are the active work, and the gap is why AIS underpins traffic awareness rather than secure tracking. The cyber dimension of a spoofable navigation feed is treated in maritime cyber security.

LRIT: the closed satellite report under SOLAS V/19-1

Where AIS shouts, LRIT whispers to a short list. Long-range identification and tracking is a closed satellite reporting system established by IMO resolution MSC.202(81) of 19 May 2006, which inserted SOLAS regulation V/19-1 and entered force on 1 January 2008. An LRIT ship transmits its identity, position, and the date and time of that position automatically every 6 hours, four reports a day, over satellite to an LRIT data center, which then distributes each report only to the administrations entitled to see it. It applies to passenger ships, cargo ships of 300 gross tonnage and upwards, and mobile offshore drilling units on international voyages.

The access control is the whole point of LRIT and the cleanest contrast with AIS. Three classes of administration may receive a ship’s LRIT position: the ship’s own flag state at any time anywhere; a port state, when the ship has declared its intention to enter that port; and a coastal state, for any ship navigating within 1,000 nautical miles of its coast, subject to the rule that a coastal state cannot demand the position of a ship that is in another state’s territorial waters. The 1,000-nautical-mile coastal entitlement is the figure that defines LRIT’s security geometry: a state sees the ships approaching it from a thousand miles out, but it does not get an open feed of the whole ocean the way AIS allows. The data flows through national, regional, and cooperative data centers coordinated by an international data exchange, with the IMSO acting as the LRIT coordinator.

LRIT and AIS are complementary, not redundant, because they answer different questions. AIS is open, continuous, local, and unauthenticated, built for collision avoidance and traffic management in the few tens of miles around a ship. LRIT is closed, infrequent, global, and access-controlled, built for flag-state oversight, port-state preparation, coastal-state security, and search and rescue. A search-and-rescue authority can request LRIT position information for any ship in a distress area regardless of the 1,000-mile rule, which ties LRIT back to the GMDSS purpose at the top of this article. The two systems together, plus satellite-AIS over the top, are how the modern surveillance picture of the world’s shipping is assembled, and the discrepancies between them are exactly what flag a spoofed or dark ship.

The position source: GNSS under both systems

Both AIS and LRIT report a position they did not measure themselves: they take it from the ship’s GNSS receiver, almost always GPS, increasingly fused with GLONASS, Galileo, and BeiDou. That shared dependency is the quiet vulnerability under the whole tracking picture, because a ship that reports a confidently wrong GNSS fix will broadcast that wrong fix over AIS, report it over LRIT, and steer to it on the ECDIS, all without any of those systems knowing the position is false. GNSS jamming (drowning the weak satellite signal in noise so the receiver loses lock) and GNSS spoofing (transmitting a counterfeit signal that the receiver tracks as genuine and that walks the apparent position off the true one) are documented and recurrent in several maritime regions, with clusters of affected ships in the eastern Mediterranean, the Black Sea, and parts of the Gulf reported through the IMO and coastal authorities.

The defenses are layered rather than absolute. A receiver that cross-checks multiple GNSS constellations is harder to spoof than a GPS-only set, because a spoofer has to forge several systems coherently. Terrestrial backups, the revived eLoran proposals and the IMO’s interest in resilient PNT (position, navigation, and timing), aim to give the bridge an independent position that does not come from space. The practical watchkeeping defense remains the oldest one: a navigator who cross-checks the GNSS position against radar ranges to charted features, visual bearings, and the dead-reckoning track catches a spoofed fix that the electronics accept. The point for this hub is that the integrity of the tracking picture is only as good as the position feeding it, and the same satellite link that distributes the report cannot validate the fix inside it.

Connectivity as the platform: e-navigation, remote support, and crew welfare

The same satellite link that carries the distress alert and the position report has become the platform for three further things the industry now depends on. The IMO’s e-navigation strategy, developed since 2006 and carried in a strategy implementation plan, is the framework that aims to harmonize the collection, exchange, and display of marine information on board and ashore over agreed data standards, so that electronic charts, route plans, weather, traffic, and port information move between ship and shore as structured data rather than voice and paper. E-navigation is the standards layer; the satcom fit is the pipe that makes it real, and the broadband step change from VSAT to LEO is what turned e-navigation from an aspiration into running services.

The data standard underneath the strategy is the International Hydrographic Organization’s S-100 framework, the successor to the S-57 standard that defined the first generation of electronic navigational charts. S-100 is a model that lets many kinds of marine data (the chart in S-101, water levels and currents, surface weather, under-keel clearance, route exchange, and more) share one structure so they overlay on a single display without a separate proprietary format for each. The reason this matters to a satcom hub is throughput: pushing live S-100 water-level and weather layers to a ship mid-voyage, and pulling the ship’s route and sensor data back, is a continuous data exchange that only the broadband links make practical. The Maritime Connectivity Platform, a related open-architecture effort, defines the identity and service-registry plumbing so a ship and a shore service can find and authenticate each other over whatever link is up. None of this runs on a 432 kbit/s metered L-band channel; it is the LEO step that turned the standards into a live service.

Remote support is the commercial payoff of the broadband link. With a LEO connection a ship can stream engine, generator, and machinery data ashore continuously, which lets an OEM or a shore technical team run the condition-based monitoring described in engine room automation and monitoring, diagnose a fault before the next port, push a software update to a navigation or control system, and guide a repair by video. The same link supports remote surveys and remote audits, where a class surveyor inspects over video rather than flying to the ship. This is the connectivity foundation under smart shipping and autonomy, and it is the hard prerequisite for any degree of remote or autonomous operation: a shore control center cannot conduct a ship it cannot reach with low latency and high reliability, which is the central constraint discussed in autonomous ships and MASS.

Crew welfare is the third use and, by data volume, often the largest. The Maritime Labour Convention 2006, as amended, has progressively recognized seafarers’ access to ship-to-shore communications and, from the 2022 amendments, internet access where reasonable, which turns a welfare expectation into a regulated one. The LEO shift is what made affordable crew internet possible at sea, because the per-gigabyte cost on a Starlink-class link is a small fraction of VSAT and a tiny fraction of L-band. The operational and the welfare traffic now share the same broadband pipe, which is why connectivity procurement is no longer a pure operational decision: the recruitment and retention argument for keeping a crew connected sits alongside the engineering argument for streaming machinery data.

The shared pipe forces a network-segmentation decision that did not exist when the only data link was a metered L-band terminal. A crew watching video on the same physical link that carries the engine telemetry and the navigation updates is a routing and security problem: the operational and welfare traffic have to be separated so a saturated crew network does not starve a critical operational report, and so a compromised crew device cannot reach the navigation and machinery networks. The standard answer is a managed router that holds the GMDSS terminal on its own isolated path, keeps the operational virtual network apart from the crew virtual network, and prioritizes the operational and safety traffic when the link is contended. Getting that segmentation wrong is how a welfare amenity becomes a safety exposure, which is the bridge into the security section.

Every one of these uses widens the ship’s attack surface. A vessel that streams machinery data ashore, accepts remote software updates, and runs crew internet over the same broadband link has far more network exposure than a ship that was an island for the voyage, and the navigation feeds it relies on (AIS, and the GNSS position under both AIS and ECDIS) are spoofable. The security consequences of the connected ship are the subject of maritime cyber security, which is the natural next read from this hub.

Limitations

This article is a map of the satellite-communication and tracking systems, not a substitute for a ship’s radio survey, its GMDSS equipment certificate, or a flag administration’s carriage rules. The sea-area boundaries given are typical extents, not fixed coordinates: sea area A1 exists only where a coast station with continuous DSC alerting actually operates, and sea area A3 follows the real footprint of the recognized satellite service the ship carries, which differs between Inmarsat and Iridium. Confirm the applicable sea areas and the required equipment for a specific voyage against the flag state’s rules and the current GMDSS Master Plan, not against the general description here.

The regulatory references are stated as in force in 2026: SOLAS Chapter IV as modernized by IMO resolution MSC.496(105) from 1 January 2024, the Iridium GMDSS recognition under MSC.451(99) with service live from December 2020, AIS under SOLAS V/19 with the air interface in ITU-R M.1371, and LRIT under SOLAS V/19-1 from resolution MSC.202(81) in force 1 January 2008. These instruments are amended periodically, and the recognized-mobile-satellite-service list can grow as further providers are approved; verify the current text of the regulation and the current list of recognized services before relying on either for a fit-out decision. The bandwidth and latency figures for L-band, VSAT, and LEO are representative of 2026 commercial offerings and vary by provider, antenna, footprint, and weather; treat them as orders of magnitude, not contract values.

AIS and satellite-AIS coverage are not complete or authenticated. S-AIS detection in busy traffic is probabilistic because of slot collision at the satellite, so an absence of a position is not proof of an absent ship, and the open AIS message set can be spoofed or disabled. LRIT, while access-controlled, depends on the ship’s terminal transmitting and on the data-center distribution chain functioning; it is a 6-hour report, not a continuous track. None of the linked calculators replaces a type-approved equipment fit, a radio survey, or a flag-state determination of the carriage requirement.

See also

• Smart shipping and autonomy: the connected ship, e-navigation, and remote support that the satcom fit enables.
• Autonomous ships and MASS: why remote and autonomous operation depends on a continuous, low-latency shore link.
• Engine room automation and monitoring: the condition-based machinery monitoring that the broadband link streams ashore.
• Maritime cyber security: the attack surface that connectivity and spoofable navigation feeds create.
• Polar communications backup calculator: the redundancy a high-latitude voyage needs across HF and satellite.
• Polar HF DSC communications calculator: the HF distress-alerting leg for sea area A4.
• Polar Inmarsat A3 communications calculator: the geostationary L-band reach to about 70 degrees latitude.
• Polar Iridium A4 communications calculator: the low-Earth-orbit global cover that reaches the poles.