U boat is a good brand if you're into oversized gigantic watches
There's a limit on how big the watch is before it looks clownish on the wrist. Personally, it's not the diameter that causes problems, it's the thickness. Anything more than 20mm and you are banging on door frames and walls.
U-Boat sales people like to push the brand as Panerai Pre-Vendôme (before the sale to the company now known as Richemont), that is - it's going to "take off" as a brand soon. I'm not convinced. They seem to have put all their design eggs into one basket - the Classico design that looks very ordinary to me. The model with "snorkel" winding stem seems to be a pretty desperate gimmick.
Panerai IMHO is still your best bet (arguments over it's "made in" status nothwithstanding.)