So my boat had the typical nylon strap holding the boat to the trailer, as well as the rear ratcheting tie downs, but there should be a secondary safety cable connecting to the bow eye of the boat.
This was an easy install and only cost maybe $10.
Go to the hardware store and buy a few feet of coated stainless steel wire, and a couple of metal bolts.
Take the cable and loop it back over itself and tighten with the cable clamps. (they are designed for this) If you want to get slick you can even add the stainless curved piece to loop the cable around but it is not necessary.
Now you will need to look at your trailer and the install may be slightly different. I was able to drill through the vertical steel tube to install the piece that bolts to the steel. Then the other side connects to a caribbeaner. I should probably replace the carribeaner with a strong steel hook like on the nylon strap, maybe that will be the next upgrade.
Viola, a simple fix and now you have a secondary cable securing your boat to the trailer in the event of a catastrophic failure of your main nylon winch line.
On a side note, sometimes my boat slips back from the wheel holding the bow a few inches, allowing the boat to bounce over freeway bumps slightly. Take a ratcheting tie down and loop it under the center support and hook both ends to the eye bolt. Just make it snug and it will prevent the boat from having any bounce whatsoever.