Good old Google. These are from the MasterCraft blog.

5.7 Ski boat package with ZF transmission. Note the proprietary intake system and catalytic converters integrated into the exhaust manifolds.

There more than "a few" of them lined up on the paint line. Apparently, there are also both raw-water and closed-cooled versions.

6.0 liter LS-based package, and stacks of 6.0 and 6.2 long blocks. This is no rumor.

LS motors are lame!

If they would build some marinized Hemi's based on the new Ray Barton designed World Product produced Mopar Hemi blocks THEN Ilmor would really have something exciting!

http://www.raybarton.com/new_block.htm

Now we just need a "Little INDY" for the V 8 `s

Lame? I don't know about that; they're just not big displacement. They make good power for their size without having to get carried away. 420 hp from a warrantied and catalyzed 6.2 seems pretty good in my book. I think that they have a lot of potential for the stock, mid-power mainstream market.

If you want to go for big power, marinizing the Ray Barton package would give you something unique and very expensive, but with all sort of custom-made marinization parts. Doesn't seem worth the effort, when there are tons of Chevy-based platforms out there, or even the new quad-cam Mercury 1350's and 1100's. Those are truly sophisticated engines.

What's the largest displacement "generally available" LS engine? The 505 hp LS7? It's not listed as a Marine engine; wonder how much work it would take. Who else is playing with marinized LS engines?

just finished mine ls 2 stroked to 403 cid whit foged rottation assembly and the ls7 drysump system mounted ,used a mast motorsport ecm package and closed cooling set of the pcm z06 . 560hp@6100 and 500+ of tq from 3000 till 6200 tops at 544@4000 rpm

It's doable but it's alot customize work the first time after that you know what to do !