Re: Trailer doesnt have a safety chain
I would go to a hardware store and buy a length of chain and a strong hook, long enough to run from the bow eye to where the winch is mounted to the trailer and bolt it there. Give yourself enough slack that it's not bound up.
It's possible you can buy a ready-made chain. Check with your marina.
Come to think of it, I like his idea better. Bolt the other end straight down or slightly aft.