46 C.F.R. § 179.210 – Collision bulkhead.

(a) A vessel of more than 19.8 meters (65 feet) in length must have a collision bulkhead.
(b) A vessel of not more than 19.8 meters (65 feet) in length must have a collision bulkhead if it:
1. (1) Carries more than 49 passengers;
2. (2) Operates on exposed waters;
3. (3) Is of more than 12.2 meters (40 feet) in length and operates on partially protected waters; or
4. (4) Is constructed of wood on or after March 11, 2001, and operates in cold water.
(c) A double-ended ferry required to have a collision bulkhead must have a collision bulkhead at each end of the vessel.