Boarding boats almost always requires a person with adaptive physical needs to be carried on board. Wheelchairs are sometimes used on board, but not necessarily. It is an individual matter. Some people need their chair for balance.
The diver and chair can be carried aboard separately. The flat-deck Caribbean-style boats can sometimes be boarded using a ramp. CAUTION: lifting someone while they are in their wheelchair can be a little risky, as the person could be thrown from it if the chair tips too far forward or if one of the carriers trips.
Mobility on board boats is often difficult in a wheelchair. If they are able, it it might be easier to scoot around, or to be carried.
For the sight-impaired, be aware of obstacles, such as equipment left lying around, and steps into the galley. Familiarize all divers with the layout of the boat by taking them around and explaining where and what things are. Have someone available to assist.
ACCESSIBLE DIVE BOAT
The dive platform (swim step) is a most important consideration. The dive platform should extend out far enough to accommodate a diver in the seated position, and have enough space to allow 2 assistants to help the diver into and out of the water. The minimum dimensions are 3 feet/1m X the width of the transom, and clear of obstructions such as ladders. The dive platform should be level with the water for easy entry and exit from the water.
The transom should be open to the deck with wide steps of 12 to 18 inches/45cm in height. This enables helpers to easily transfer the person to and from the dive platform. The deck should have enough space to allow a person in a wheelchair to freely move around. To turn around in a wheelchair they need a minimum space of approximately 5 feet/1.5 meters X 5 feet/1.5 meters, with 4 feet wide walkways.
There should be an area available on deck with shade to get out of the sun. When possible, it is most convenient if the deck is even with the dock or pier for ease of boarding.