Now the N. Atlantic is a wild and wooly ocean and a sub could breach on a wave with a massive 'trough' fore and aft allowing the bow to be exposed and the propellers to bite air for several revolutions but your waters appear mostly calm and flat.
I think a submarine modeler is doing themselves a disservice by not viewing the entirety of Das Boot beforehand--one of the best depictions of WWII submarine warfare, if not the best, ever.