Hello I am a new user. I have a 1 year 31 Coronet seafarer with 2 aqad40b and Volvo penta 280 outdrives Duoprop. I tried the little boat, but I have a big doubt about the installation that have made feet. I wanted to ask if anyone knows for sure if the 31 coronet the outdrives have to be fitted with the extension. In my case the anti-cavitation plate is 7 cm higher than the hull edge. Thank you all for this wonderful club. Regards.

No one?

Hi Fiorello

According to my knowledge, the cavitation plate must be level with the hull edge
This means you need the extension on your outdrive

Google: cavitation plate height
Then you see many examples

IF there is a problem with the propellers loosing grip and too much slip, You may have to use extentions, but if it works as is and the boat run well with good performance, there is no reason to lower the drives. Cavitation plate in level with hull bottom is old school conservative installation. I think 2"+ as on your case is not extreme in any way.

Agree with Dag, he put it very well. Unless you have problems with propellers ventilating or difficulties getting onto plane, there is no need to make any changes. Also worth considering is that if you do have propellers ventilating, better propellers may be preferable over lowering the outdrive legs.

Good luck & happy boating!