The fin does submerge due to the fact that it's hollow and there is a square cut out near the top that is camouflaged with screen painted at the same time as the fin.

Found this , goes well but no swim action 😟


http://bateaux.trucs.free.fr/jojovideo.html

Alex does that fin submerge?

Paul

Ha haa very dramatic Alan 😊 , good to hear no wind up swimmers we're hurt in the making of that film

That looks really realistic in the water, if a bit on the large side.

Did you come across this one. 😁


Alan

Found this , think it's about as close as it get's , need some specs and designs now 😊

No shark body but a shark fin, I can help with that part
Alex