Pat,
Welcome to the pub. I think I recall reading on one of these threads that one would cut out a hole for access to the top of the gunnels and then cover it with an access hatch. Do a search in the search box on the top left side of the page and you might find what I'm referring to.
Dwight (aka Chromer) owns a 19' Angler, Checkpoint II and he's quite a fisherman with downriggers set-up. Maybe he'll chime in.
**On Edit** I was right. Here's what Dwight did. Just as I described. (Nice linger Michael!)
Thats great, thanks for the help and that is a great fish!