I run a 5 degree tunnel on a 20' predator with a 150 and it runs great in all shallow water applications. Where it does not run great is in big water. I spent a little time in 3-5' rollers in heavy whitewater and it tends to cavitate and lose power. I had to really feather it in the big water to keep it moving. If you were looking for a boat to run nothing but flat shallow waters, the tunnel is awesome. They go through 3" of water all day long. Less than that and you will find bottom. The nice thing about finding bottom in a tunnel is if the bottom is gravel or sand you blow right over it. If it's big boulders you are in trouble. Don't back off the throttle or you will be there a while.