I've read that the 311 has a light rocker (opposite of the hook on the smaller hulls). Maybe the information was wrong, who knows.

My indicators for the trim do not go to 0... they're adjusted so that they're on the hash mark between 0 and 1 (maybe a little closer to 1). She was like the this when I got her.

Ive thought about adding water up front to smooth her out.

When you say neutral, is that with the cavitation plates being in parallel with the running surface or with the waterline?

I had a different drive but my experience was run the drives neutral no pos or neg trim. I used my tabs more than anything when on plane. I would try that n stead of tucking the drives to get rid of a porpoise. I would cruise 40 at 3800.

It's doesn't matter what the number is on your indicators as long as you know where level is. I think you might need a little cup put in your props to carry the bow better. What's happening is it's catching and lifting the bow and falling again. And will just keep going like you're on a trampoline. Are the props Plus or straight Mirage ? Also dropping some tab won't hurt while cruising.

They're Mirages. The concensus seems to that the 311 likes the Mirage and not the Mirage Plus. I wish I had a set to try. If I moved to a Mirage Plus, I'm thinking the right one to try would be a 25P. This could be a prop issue... I remember that our Cigarette Bullet porpoised a good deal running these props (they came with the boat). We went to a set of Bravo One 26P's and the boat loves it.

Dropping the tabs doesn't seem to help much, unless I really drop them.

I have everything marked. Again, what's considered level? Cavitation plates level with the running surface, or level with the water line/ running attitude? I'm thinking running surface... if that's the case I'm way off from running her at level (on the indicator).

level = propeller thrust in a straight line from running surface i.e. neutral trim

Straight edge on bottom of boat, set your drives till prop shaft is on same plane
Tabs: straight edge on bottom of hull sticking out under tab, measure distance front and rear to make equal. Notice how high tab is mounted on transom back edge make the same.
Don't be afraid to play with the tabs, do the equal/same time a stab at a time and give the boat time to react,
back edge 2" down at cruise is not a lot,

That's how I have her set up (I have thin red vinyl tape marking neutral), and I am never able to get even close without porpoise setting in.

I'll give it a try over her weekend.

Speaking of which... I need to plan some time where it's just me and the boat... no plans to meet anyone or hang out. Seems something's always going on. We've been using her a lot, and it's not even summer (this is a good thing), but I need some one-on-one time with her to explorer her settings and boundaries and such.

FYI... Going to cross-post this in the prop forum. I'll keep both threads updated.