No, not the GAM antenna. I haven't evaluated that one; Gordon West has, says it's OK, but I have my doubts. And, it's damned expensive for what it is.
Basically, you just take a piece of s/s insulated lifeline, 23' long or more, hoist one end with a spare halyard, and tie off the lower end at the leading edge of the pushpit...either port or starboard. Locate the automatic tuner as close under deck as you can. Then, take a length of GTO-15 insulated wire and connect the tuner to your "alternate backstay".
You do, of course, need an RF counterpoise or ground system, just as you do with any end-fed antenna system.
Here's a pic showing the lower-end detail. You don't need the standoff insulators; I just had some spare time one winter and fabricated them from some teak lying around the shop and some glass insulators, but used the antenna successfully without the insulators for over a decade before that!
Also, you don't need the in-line insulator(s). I just used a 2' length of 3/8" dacron braid for many years.
Simple, cheap, equally effective compared to a traditional backstay, no danger of losing the backstay if an insulator breaks, etc., etc.
And, it's easy to work on if you need to; just loosen the halyard.