It also depends on the size of the boat. I've been on a large yacht catamaran[0] that did 16 knots. It was fast, but not terrifyingly so on a boat that big. I b

It also depends on the size of the boat. I've been on a large yacht catamaran[0] that did 16 knots. It was fast, but not terrifyingly so on a boat that big. I bet it could go quite a bit faster if the owner was willing to push it, but he wasn't because it was also his home. [0] 15m long and 7m wide.