An accommodation ladder is a portable flight of steps down a ship's side.
Accommodation ladders can be mounted parallel or perpendicular to the ship's board. If the ladder is parallel to the ship, it has to have an upper platform. Upper platforms are mostly turnable. The lower platform (or the ladder itself) is hanging on a bail and can be lifted in dependence of the local needs.
To prevent the damage of boats going under the ladder in case of alternating water level it has a boat fender in prolongation of the ladder.
The ladder has a handrails on both sides for safety. The construction of an accommodation ladder guarantees, that the steps are horizontal in each angle of inclination of the ladder. On the lower part the ladder/lower platform is based on a roll to compensate the motion of the ship relation to the quay.
For boarding of maritime pilots it is prohibited to use a Jacob's ladder instead of the accommodation ladder.