Hi Scott,
Jill ordered hand-rails from the factory. One of our best purchases. This was done after we took delivery installed at Lake union.
I constantly see people grabbing them to come on board (proves the purpose) and it works well for a rod holder as seen in the pic and ideal for a deep six to catch dinner, as proven on
EmBark last summer.
For downriggers, I mounted my scottys on the Bullfrog using the mount shown above in this string and below. You can see I cut some starboard for a plate to the contour to the plastic "rib" of the boat.
Scotty Downrigger Rail Mount | Bass Pro Shop
It works well. However, the 10' bullfrog is nearly hard to starboard trying to go straight dragging a 12-pound ball at 100'. Just makes it that more fun when you spin counterclockwise when a big king hits
On the Helmsman, when Jill asked for the extra stern rails, she basically said where to place them regarding it's length. They made them in the factory and shipped them on the next vessel shipment. I was there at waterline when they installed them, but I didn't think of the application for a Scotty downriggers.
They placed the rails dab in the middle of the gunwhale which makes sense, but doing so didn't allow enough space for the starboard plate. The rail needed to be offset inboard which would look a bit weird on a normal day without a scotty mount. Plus fishing on the Helmsman, I would need to punch more holes in the boat for the 12v connections wiring etc.
So I made the dingy the fishing boat which is a lot better for running fast, find bays and points miles away from the anchorage. The drawback is you are limited to one person, two max and I would not run out many miles from shore.
So if you want others to be a part of the fishing experience, I would consider a simple rod holder and a deep 6. Try that for a year. It’s a cheap option and works well for me.
Especially if you are heading north where the fish are in the inside passages if you can stand going 1-2 knots.
Important for the trawler - I also NOW understand there was (is) an option to enable the transmission to run at a lower RPM for trolling.
Trolling valve (mechanical) for slow-speed drive. Some folks order this option. I didn’t know it was available. I’m not looking into it now because I elected to fish from the Bullfrog.
ZF 85 A Marine Transmission | ZF Hurth 85 A Marine Transmissions (tadiesels.com)
If your going for Kings without this option, you'll find yourself throwing in and out of gear as our Helmsman was a bit fast at idle..
I am confident the rail if like mine (see pic above) is sturdy enough for a down-rigger. I took a few moments as we cruised up into Canada today to think about a bracket that can work for you. Considering the force the moment with a arm at 3' using a 12 pound ball at 3 knots is about 36-40ft-lbs, however I would rate it to the breaking strength on the downrigger line which would bring it up to 80x3 or 240 ft-lbs or close to 3psi on gunwhale bracket I would consider which isn't much. I would design a plate made from starboard that not only rests flat on the outside on the gunwhale but has a brack pulling up on the short side of the handrail.
The opposing force on the long rail and short rail distributes the load. Plus I would also look at an additional support on the bump rail on the outside of the tunnel. Not sure how, but with some starboard in hand, one can look into.
Here is a rough sketch on my thoughts..
Obviously, I’d construct a prototype out of cardboard of plywood for fit and thought before finalizing and constructing the starboard bracket.
Doing this route means you'll have two large plate brackets, downriggers, 3 or so 12 pound balls, downrigger spare part tackle box, to store somewhere vs a simple rod holder.
Or consider this.. Here is a video on the deep six,
Deep Six
I don't typically use a flasher or anything else that creates drag. Caught lots of Coho and Kings using this.
I have 4 or 5 of these in my spare parts tackle box in the Laz on the way up to Alaska. We could only store a weeks-worth of fishing, which was a couple of kings, 6 or so coho, a chicken hali and many rockfish, ling and seabass fillets and one sole.
The bad news is the coat of shipping fish back. One big hali and your full on the deep freeze in the basement. Don’t do the $/lb math versus costco, it never works.
Luhr-Jensen Deep Six | Fisherman's Warehouse (fishermanswarehouse.com)
Lastly, check out comments on the trawler forum on fishing, interesting reads:
Fishing suggestions on a trawler | Page 2 | Trawler Forum
Good luck and let me know if you come up with a solution, and see you in September.
Tom