I have flown 3 or 4 Seamasters with different engines on them from 45 to 50 and all fly fine - they need to have the right prop. My Seamanster flys great on a Enya 50 CX with an 11 x 6 APC prop. Just silicon on the tip floats, the velcro is not good. The tip floats don't affect flying from land either.