http://www.overtons.com/modperl/prod...FZm6wAodCwENyQ
Get these. Or something of this style- these are probably the same ones from an above post. Rear tie downs are designed to keep the boat down on the trailer from moving- not so much from falling off- so you don't need to have them so tight they can't be removed. That's where your safety chain comes in. This style is what you need.