don't have a good pic, but I have welded a pair of plates on our harness spreader bars where some small harken cam cleats are bolted. The boat has a line running from beam to beam that retracts into the rear beam with a bunji but deadstops when pulled out to the correct distance. We step under the line and drop it in the cleat in one or both directions.

It's not perfect but it works. I can't get mine engaged on my own when I'm driving - it takes my crew to lock me in. In my case, I could probably do some work with the cleat angle to make it easier. The benefit of the cam cleat is that they will release at high angles and it will let you go when the $hit has hit the fan and doesn't keep you locked in forever and forever.