Non tunnel can run in a foot, get up in two.
Tunnel when it's setup properly can run in 4" get up in about a foot.
Tunnel will cost you speed, lot's more water drag, and it won't handle as good. Which on a flat bottom tin boat isn't exactly it's strong point anyway.
Really depends on what bay you're wanting to fish. Galveston? Meh, not much help. Port O'Connor and south? It's a really big deal.
Marble Falls/Seadrift TX