This Low-Profile Swivel Base is only 1-1/8" tall. It has six-point locking, including two 45° positions. 5" x 5" x 1-1/8". Screws included. Fits all Cannons except the Mini-Troll™.
The Cannon Tab Lock Base is designed for small-body downriggers, Easi-Troll™ and Mini-Mag™. 5-3/4" x 5-1/8" x 1-3/8". Screws included. Available: Tab Lock, Low-Profile Swivel.
I have used my Cannon downriggers on 4 different boats in Southeast Alaska over the last 25 years, and it is an effective and simple system. These tab lock bases make it easy to remove and stow the downriggers when not in use. However, I have had some problems with the flange on the top of the base (the one that surrounds and holds the downrigger) cracking and eventually breaking. This is why I am ordering new bases and a new downrigger now. I have lost one downrigger (with a rod and reel) overboard altogether. This can happen quickly when you hit the sea bottom with the trolling lead, something that is eventually going to happen if the fish are close to the bottom and you are going after them. I suggest attaching a lanyard around the downrigger that can be snapped to the boat rail as a backup in case the tab lock base fails. Make it so that it is easy to use, and it will be there to prevent losing the more expensive downrigger, not to mention a rod and reel. The other thing I do now is to attach the trolling lead to the downrigger wire with a loop of cord that will break before the cable or downrigger base, so that I just lose the lead, nothing more.