Can your yacht enter Simpson Bay Lagoon

Describe the yacht in its arrival condition

Length overall, or LOA, describes the vessel’s full length. Beam is its width; the maximum relevant width can include fixed projections beyond the main hull. Draft is the depth below the waterline, while air draft is the height above it. Gross tonnage, often shortened to GT, is a measure based on enclosed volume rather than the vessel’s weight. Each answers a different question in a port enquiry.

Use the expected arrival condition rather than a brochure alone. Fuel, water, stores and ballast can change draft and trim, the fore-and-aft attitude of the vessel. Equipment configuration can affect air draft. Record the units beside every measurement and avoid treating rounded feet-and-metres pairs as interchangeable when margins are small.

Use published figures to screen the enquiry

Port St Maarten publishes general lagoon-access figures of 17 metres maximum beam and 5 metres draft, alongside rounded imperial values. These are public planning figures, not a fresh survey or an individual transit approval. A yacht near a limit needs the controlling information and an explicit discussion with the relevant authority and receiving facility.

There is a separate distinction between a bridge’s opening width and the height beneath it when closed. SLAC quotes approximately 8.5 feet of closed clearance, varying with tide. That number does not describe the navigable width through an opened bridge or certify passage for a tender with raised equipment.

Follow the route beyond the entrance

The allocated berth determines what comes next. An internal crossing, channel section or turn may be more restrictive than the sea entrance, and the room needed to turn is different from the space needed to lie alongside. Ask the receiving marina to identify the approach to the actual berth, including relevant temporary restrictions.

Depth also needs context. Under-keel clearance is the water remaining beneath the yacht; a quoted water depth alone does not establish the margin available throughout a movement. The captain’s passage assessment must account for the yacht and conditions using current navigational information.

Manoeuvring limitations belong in the same discussion. A propulsion or thruster restriction can change the assistance or conditions required even when the static dimensions fit. Written acceptance is useful evidence of what was agreed, but it does not replace the captain’s assessment or live operator instructions.

Check the departure condition as well

A vessel arriving light may leave with more fuel and water. A berth selected for an engineering visit may also need to support a departure with a different equipment configuration. Make those changes visible at the enquiry stage; arrival acceptance should not conceal an unresolved exit.

After the route is accepted, use the bridge transit guide to plan the movement itself. Add the dimensions, loading changes and constraints to a Sea Grapes arrival brief, with the date and source of the supporting information. That gives the shore team a precise question to resolve instead of a general request to confirm that a large yacht will fit.