A low cost and easy approach:
I use a preventer that I made out of a length of line and a couple of snap hooks (SS but not shackles). One hook is tied about 1/3 of the way, the other is kept on by a loop on the long end. While running, I clip it to the bale and forward to the toe rail. I send the line thru the loop than tie a single knot, sending a loop through instead of the bitter end. I can install in seconds without going forward or removing my boom vang, In an emergency, a quick yank and she's free. Now, this probably wouldn't work fro one of the big girls, but us trailer sailors will do just fine with this sort of Yankee-ness.