Uboat? Do you mean the Jumpmaster? It doesn't look anything like a u-boat
Uboat, name given to the Jumpmaster 5000 due to it physically resembling a "U" or horseshoe shape, as well as its effectiveness as a torpedo platform that can be flown in "swarms" (anything 3 or more is considered a swarm for large ships don't judge me!) Giving it the impression of a WWII German u-boat. Other names include bumpmaster (a collaboration of stating it's effectiveness as a blocker and a spin off of its own name), super blocker (a tip of the hat to super dash and his ability to block aces with his large base), and toilet seat/croissant.