Knowledge category
Measurements and Specs: facts
LOA, LWL, beam, draft, and displacement describe size and operating envelope.
Air draft matters for bridges; draft matters for depth and haulout planning.
Published displacement, ballast, sail area, and tankage can vary by model year or option package.
Ratios are comparisons, not verdicts. Use them with the original measurements.
Specification Fields
LOA / LWL
Overall length and waterline length.
Beam
Maximum width of the boat.
Draft
Depth below the waterline required by the hull, keel, rudder, or drive.
Displacement
Boat weight as usually published for a defined loading condition.
Real boats vary with gear, fuel, water, crew, and refits.Measurements and Specs terms
Each link opens the exact terminology entry with a definition, example, aliases, and related terms.
Air draftThe height of the boat above the waterline, usually to the masthead or highest fixed point.BallastWeight placed low in the boat, often in the keel, to improve stability.BeamThe maximum width of the boat.DisplacementThe weight of water displaced by the boat, commonly used as an approximate boat weight.DraftThe depth of the boat below the waterline.KnotA speed unit of one nautical mile per hour.LOALength overall, usually the total length of the boat from forward to aft extremity.LWLLength at the waterline.Nautical mileA marine distance unit equal to one minute of latitude, about 1.852 kilometers.Sail areaThe measured area of the sails, often listed for main and foretriangle or standard working sails.
References
Sources and Method Notes
Boatpedia reference
Open sourceBoatpedia terminology reference
Marine vocabulary reference for definitions, aliases, examples, and related terms.
Next reference
Related Boatpedia Pages
Boat DataBoat Measurements Explainedfoundation / 9 minLOA, LWL, beam, draft, air draft, displacement, ballast, tankage, and capacity describe different parts of a boat record.Boat DataSailboat Ratios Explainedworking / 10 minD/L, SA/D, ballast ratio, capsize screening, and comfort ratio are derived indicators. They help compare designs, but they are not complete judgments.Sailing ReferenceHull and Deckfoundation / 6 minThe main physical parts of a boat, from underwater structure to cockpit and steering gear.