Trolling Bar Help

[MEANMACHINE]

I am going to try and install a trolling bar on the back of my Bayliner 185. The only place that I think will be strong enough is on the back deck/swim platform. I plan to use 6" Bert's track and mount two 12" custom made risers. The deck itself does is already reinforced with what looks like 3/4" plywood. I want to make it as strong as possible so my questions are:

What material should I use for additional backing? Starboard, plywood, steel?

Should I back the mount with the largest amount of material to help distribute the load?

How long should the booms of the downriggers extend past the prop of the I/O?

Thank you for your help.

Bradley

[Priority1]

I have used plastic cutting boards as backing material. They are inexpensive, tougher than nails, and will not rust, bust, or break your trust.

[Line Dancin]

I like having more than just washers holding my rigger board. i would make backers the size of the piece of track out of 1/8 in aluminum and then bolt through that. As far as length of booms you may want 4 fters to get away from the outdrive.

[Paulywood]

I actually used to fish out a 20' Regal bow rider and one of my friends fished out of a 18' Glastron bowrider. We had the same issues as you did, but used 2 different solutions. Maybe this will give you some ideas. My friend went the route you are thinking. He made some 3/4" thick aluminum plates that he mounted to his swim platform. He drilled and tapped them to bolt his risers. He had easy access to the bottom of his swim deck so he used treated 2x8's underneath as backing. I went another route. I had some aluminum brackets made up that bolted where my cleats were mounted on the rear of the boat. This area was almost 4" thick with fiberglass and wood. These were 1/4" aluminum with aluminum angle iron welded as short risers that went to aluminum plates that my trolling board mounted to. I used diamond plate as backing. I had 2 downriggers and 4 rod holders mounted on it and it was as solid as a rock. After I had mine made I found out about a product called Eagle Feet (I think) that clamp on to the cleats. Then you can mount a board to them. I might have some pics lying around of both setups if your interested.

[MEANMACHINE]

I am going to go with the platform/deck mount. If you are familiar with the Bayliner 185 the deck does not extend past the rear off the boat. It should work with reinforcement. I am going to consider either rigging additional support to the side cleats or rope harness on the back. My only fear is making it too rigid outside of the bases. Hopefully the wife won't be able to say "I told you so" if I tear the back of the boat off.