hey thanks for the nice comments.
Yes I have trim tabs and try to use them often to get up.
Problem is that when I do, it seems to make the problem worse in some cases by making things feel like there is a large amount of viabration.
When its fully up and at WOT and trimmed out, it runs 4600 rms @ 39mph by GPS.
But its hard to get up and in the middle of the rpm range the drives vibrate and it sounds just like cavitation.
Once up on top of the water, it runs sweet and effortlessly.
Low rpms while pushing through the water its not a proble either.
Now, if I am up and running along, I can duplicate the sound and feel and problem by pushing the tabs down or, by trimming up the drives a bit too much.
Its the identical feel and sound as the motors make while routinglyi trying to get up on the water.
If I ease through it or baby it through it, it will be fine,
ps by the way, I have 220HP Mercs x2 and bravo 3's
Maxum 3100 SE
5.0 Mercs 220HP x 2