Bow flare

Bow flare is the outward curvature of the forward sections above the waterline, so the deck overhangs the waterline beam at the bow. Flare adds reserve buoyancy forward, throws spray clear of the deck, and reduces deck wetness, but it raises the rate at which buoyancy builds as the bow plunges into a wave, which drives bow-flare slamming and whipping loads on fine fast hulls. Class rules (IACS UR S and the ship-specific slamming-pressure procedures) treat flare slam as a design pressure on the forward shell and stiffeners. The design trade is direct: more flare improves dryness but worsens slam loads, which is why wave-piercing forms such as the axe bow use almost none.