What Is the Draft of a Boat?

Draft is the number that decides where a charter can actually take you, and it is the one most guests never ask about. Biscayne Bay is broadly shallow, and the sandbars that anchor most Miami itineraries sit in water that can be only a couple of feet deep. A boat drawing five or six feet does not get close; it anchors on the edge and shuttles guests in by tender.

Hull type drives the number. A sailing catamaran typically draws around one metre, against two metres or more for a ballasted keelboat of similar length, because the catamaran generates stability from its beam rather than from a deep keel. Power catamarans and shallow-vee center consoles sit shallower still. Deep-vee motor yachts and anything with large propellers, shafts, and rudders sit deeper, and on those boats the lowest point is often the running gear rather than the hull.

Draft is not a fixed figure. It increases with load: fuel, water, provisions, and a full guest list all push the hull down. Some vessels quote a light draft and a loaded draft, and the loaded figure is the one that matters on a full-capacity charter. Sailing yachts with lifting keels or centerboards can adjust draft, trading upwind performance for shallow-water access.

Combine draft with tide before you plan anything. Charted depths are referenced to a datum, not to the water in front of you, and a passage that clears at high water may not at low. A competent Miami captain plans a sandbar stop around the tide window for that specific hull. When you compare boats, ask for draft in feet, not adjectives, and ask whether it includes running gear. If a listing quotes draft in metres, remember the practical conversion: one metre is roughly 3.3 feet, so a catamaran drawing a metre needs about four feet of water with a margin for swell and squat.