If you have ever had the pleasure of cruising in Maine, you are aware of the abundance of lobster pots. Some areas include a warp with a toggle along with the lobster pot, just to make it interesting. :o
Consider adding a skeg to your strut that will help prevent being hung up. I still pay close attention though..
(http://i357.photobucket.com/albums/oo18/jmbjr2/Power%20boat%20prop%20with%20Skeg_zpse76pwstq.jpg)
that's a pretty slick setup, I bet it would help deflect bull kelp as well. Thanks for sharing it!