Alpha-Centauri Speedboat - photo shoot in the sun

[@squidkid2]

You need to add some hydraulic trim tabs to get the hull up on a plane. The boat would be much more stable and a lot faster in a planning configuration. Also you need a full face helmet and a neck collar to prevent whiplash if you're going to be doing top speed. If you hit a rough patch and struck your head without a helmet you could get knocked out and the lanyard would still be plugged in and you could keep going while unconscious. Any boat that can do 60 mph will eventually have some kind of mishap and being out there solo could lead to a bad day quickly. Unless you have a fast chase boat to rescue you you're on your own out there regardless of what happens. Boats like this are race boats and can't be treated like regular boats. Much like a Ferrari takes a skilled driver to stay out of trouble. Your wide open throttle problem could be a prop cavitation issue. Flat bottom hulls are prone to instability in the area where the hull skims the water surface. If the water that the prop in going through becomes turbulent the prop can't bite. It's the difference between solid water and water with air bubbles. Every race boat design is unique and like a sports car the design needs to be tested under real world conditions to dial it in.

[@geoffburrill9850]

Think you need a touch more weight forward or some trim tabs aft.

[@1967friend]

Followed your entire build. Amazing work! It sure appears that the boat has a porpoising problem. Perhaps move some weight forward, or add some downward trim on the out drive. If you can get the front end to calm down surely the ride would be much better.

[@BoatsandEngines]

Hello, yest its sorted now after playing with the trim. Its a bit harder than with a modern outboard as it does not have power trim, so the boat has to come out of the water to adjust each time.

[@kclaptraffic]

@@BoatsandEngines trim tabs would help as well with fine tuning. They also work well to keep the sponsons in the water to help with quicker steering. Power trim tabs can be built light and cheap as well, so you can adjust on the fly.

[@johnd.ingleson799]

​@@kclaptraffic ' _trim tabs_ ' Are those adjustable horizontal aerofoils? Would a rear horizontal aerofoil, like the old Supra's and my old MR2 (just for show?), but adjustable (maybe using an modern F7 RC flight controller and servos???), be efficacious for horizontal stability, or perhaps bears still sh*t in the woods or am I still talking nonsense? ;-) TIA

[@johnd.ingleson799]

Awwww! Wot? No drone-cam footage? - 'Great vid and photos, though.