Boats aren't made of dry wall 
Anyway the question wasn't whether it would penetrate one side but whether it would penetrate both sides. I haven't seen a picture of the starboard side of the boat (nor anything else downrange 
).
Of course, inboard engines, bronze fittings, and terrorists would tend to slow down or stop bullets even more than the topsides.
That's pretty much what I meant, though I wasn't clear in my OP. Wonder if the aforementioned TAP, or similar, rounds would go through-and-through? I'm leaning towards no, but have little to base that on in fact.
http://www.theboxotruth.com/docs/theboxotruth.htm
Interesting - wonder if the testing page I'd seen in the past was deliberately shooting at the 2x4s in the "interior walls" they used for testing? Though it didn't look like it from the pics, frankly. They got much lower penetration than BoT, though it looks like BoT only used FMJ (which on the other site did in fact penetrate all three "interior walls" and keep on going - it was only the low-penetration TAP/frangible types that didn't punch through at least two full walls, IIRC). Looks like BoT #4 tested a .223 round generally similar to the ones I saw on that other page, which for BoT penetrated 4 walls' worth of drywall (8 sheets). <shrug> Looks lie similar penetration of walls to 00 Buck, and far more controllable by a small-framed individual; you have to aim either weapon (AR or shotgun) and you've got 30 shots from the AR versus a practical max of 8-9 even from an extended shotgun mag, so I'd still give the advantage to an AR, it's just not quite as safe to bystanders as I'd been led to believe.
It does look more like rounds that missed whatshisname in the boat probably had a good chance of going through-and-through, though.
