This feels contrived, to be honest. Late at night on a vehicle that isn't moving with no other discerning factors to distinguish things, and you are basically screwed. Though, realistically, you are just going to wherever the shouting is coming from, you are not going to go slow to orient yourself to the vehicle. Even better, someone would yell something even more defining for where to catch someone that is going to be specific to the boat you are on. (Well, more realistically, you have hopefully practiced emergency drills such that the term is almost irrelevant, you have practiced so much.)

This is about as worrisome as "you are the fire department, and you are told you need to rescue some people on the 14th floor. Quick, does that mean you go up 13 flights of stairs, or 11?" Realistically, you aren't getting it right on spur of the moment decision making.