I would only replace it with Honduras Mahogany.
If you use another species of wood, like cypress for instance, the coeeficient of expansion will be different. This is, the diferent tpes of wood would expand and contract diffferently and would either force the adjacent pieces apart and cause splitting or in the other direction, the wood would shrink differently and leave large gaps.
Honduras mahogany is a quality mahogany. It does not expand as much as most other woods when wet. Cypress, onthe other hand, expands (swells) quite a bit.
My first choice would be for Honduran Mahogany. Sometimes, depending on the type hull you have, and the placement of the wood would also determine if an alternate wood could be used.
Is your hull planked, lap straked, or something else and how big is your boat and what style boat is it?