Boat Data

Boat Measurements Explained

LOA, LWL, beam, draft, air draft, displacement, ballast, tankage, and capacity describe different parts of a boat record.

Level
foundation
Read time
9 min
Sources
1

Profile Measurements

A side-profile diagram helps separate length, draft, and air draft without embedding measurement labels inside the graphic.
Length overall
The maximum overall length of the boat, often including fixed bow or stern structures depending on source convention.
Draft
The vertical distance below the waterline to the lowest fixed point, usually keel, rudder, or drive leg.
Air draft
The vertical clearance above the waterline, important for bridges, rigging, and covered storage.

Primary Dimension Terms

LOA

Length overall: the maximum length of the boat as reported by the source.

Sources may handle platforms, pulpits, bowsprits, and outboard brackets differently.

LWL

Length at waterline: the hull length touching the water at a stated load condition.

Useful for displacement-speed context, but load and trim can change the actual waterline.

Beam

The maximum width of the boat.

For multihulls, beam affects marina fit, transport, and motion more dramatically than on many monohulls.

Draft

How much water the boat needs below the waterline to float clear.

Keel options can make draft variant-dependent.

Measurement Fields on Boatpedia

FieldMeaningBoatpedia use
DisplacementApproximate weight of the boat at a source-defined condition.Supports trailerability, performance ratios, handling expectations, and transport context.Lightship, half-load, and full-load displacement are different values.
BallastWeight placed low in the boat to improve stability, usually on sailboats.Feeds ballast ratio and helps describe keel/stability design.Ballast ratio alone does not describe hull form, center of gravity, or ultimate stability.
TankageFuel, fresh water, and holding-tank capacity.Helps estimate range, cruising autonomy, and owner fit.Usable capacity can differ from nominal tank capacity.
Bridge clearanceClearance needed to pass under a fixed obstruction.Important for powerboats, canal routes, covered slips, and low bridges.Electronics, antennas, outriggers, and hardtops can change the practical value.
References

Sources and Method Notes

Boatpedia reference

Boatpedia reference standards

Public guidance for reading model facts, source notes, market context, and data caveats on Boatpedia.

Open source
Next reference
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.Boat DataKeel Types Explainedfoundation / 8 minKeel type affects draft, stability, leeway resistance, grounding behavior, maintenance, and where a sailboat can operate.Boat DataHow Boatpedia Verifies Boat Specificationsreference / 8 minBoatpedia treats specifications as cited facts with confidence, source type, unit normalization, and variant scope.