Aft or stern rail, or taft rail ifthere a combination of bulwarks aft & stantions amid ship. You may be on the main, upper or lower deck. He might be listening to the engine (I don't know how loud a steam engine would be though). He might be looking at the wake, sea birds, not dolfins, I've only seen them play in the bow wake or along side, never seen they play prop's (screw's) wake. You might be able to see them from the port or starboard stern rail though. The rail maybe supported by stantions (vertical metal pipe like supports) or bulwarks (like a solid wall) which would mean you may want to call the rail a rail cap. There wold be hold in the bulwards. Those holes if level with the deck would be called scuppers though which onboard water (green seas) would drain or could be used to pass lines through. There may also be cleats in board of the stantions (or bulwarks or they may be mounted of the bulwarks themselves. There maybe davits aft or along side from which life boats are hung or he may just be viewing the land he just left behind. There are many books that describe ships in detail Chapman's being one, Royce's Sailing Illustrated being another. There's plenty of boat building & design books & such that you would do well to take a glance at.
Good luck, hope I've been some help.
Barry