I hope the criminal court would have something to say about caltrops used that way, even in the US. While you are at it, why not just rig a claymore mine on the boat. "Front toward enemy" seem to be a concept you understand and like.
Too much collateral damage. I'd be spending more time cleaning guts off the tramp and patching the ball-bearing-sized holes in the hulls to actually go sailing.
But caltrops now, would be perfect!
