Matt's (Ring King) example is a very good way to secure the H-Rail. I ended up taking a 21 inch H-Rail kit and make the accessory bar seen here.
https://www.hobie.com/forums/viewtopic. ... ll#p281696I ended up using a little Marine Goop on the nuts to hold them on the washers and was able to reach the bolts enough to get the nuts started on the ends. Then it was a matter of using a screwdriver on top and a socket wrench with an extension to ratchet it snug. It is a stretch!

If you're using the rail that low, it would work fine for rod holders or anything that is going up and not hanging lower than the rail. I wanted mine elevated so the scuppers and the cart would not be impacted and have some room under the tackle tray. You might have to shorten the rail a little looking at your picture. If you leave it as the picture shows, it will impact the taco clip on the left side.