Well - IF he's offering you more than the courts would give you, get him to get it in writing ASAP! But honestly - you should NOT be having those financial discussions without legal advice. And anything he says now isn't worth the paper it isn't written on.
I do recommend mediation as a less expensive and combative way of doing things. You should have your own outside lawyer too, though, in addition to the mediator, and you should meet with them first so that you have a really clear notion of what is fair and appropriate. You also need to give yourself some negotiating wiggle room, so it's good to ask for a little more than what you are aiming for.
If he plans to keep the boat, how will he be paying you for your share of that asset? Or is there no equity in it?
