I shouldn't say this, but I have never sunk my F-5 it runs great on water!
We had four of us out 1 05 mxzx race 440, Rev 600, RMK 700 144 and my F-5.
I did do some jetting this year and man that really woke the machine up. We did have the 440 sink, it must have got a bit of water in it. We always tie a 100' rope onto the a arms and coil it around the gauge pod with a boey on the end so all you do is rip the rope and there you go its marked.
We do need to find a old pontoon to cut up and make as a rescue boat.
Floating ramps would make it fun too!