How do you slow down a 36', 20,000#, 420hp behemouth?

[Mariner]

Around here, if you want to catch Salmon, you've got to get your trolling speed down under two knots. Nordvika idles at 3.5 knots even in the "slow engine" mode.

Short of mounting a small outboard to the swimstep, does anyone have any ideas of how to slow this thing down?

[jcollins]

We have a similar problem around here. Trolling for Rock. Isn't there some type of trolling valve you can add to the transmission? In my case it would not be worth the expense since I don't troll that much. I'll do some research and post later.

[jcollins]

Found this at boatdiesel.com. I not registered there.
http://boatdiesel.com/Forums/Index.cfm? ... CFIDC=NRU2

[Mariner]

A trolling valve is an idea, but rather expensive considering that I, like you, don't really fish that often. Plus, I'd like to have some sort of emergency get-home power. I know there are kits you can buy that attach a belt or chain drive to the propeller shaft and are driven by a hydraulic motor that gets it's power from the genset.

What I really wish I could find would be a very high thrust electric trolling motor; preferably one that ran on AC power so I could power it off the genset. Also, I wish you could get diesel outboards in the US. That would mean that an emergency get-home motor (and possibly a tender motor) would run off the same fuel as the main engine, eliminating the need to carry gasoline on deck or in the lazarette.

But it's wishful thinking. I've looked and looked for high-thrust AC powered trolling motors and no such thing exists. And while Yanmar does make a 25hp diesel outboard, you can't buy it in the US. Something about emissions standards.

[jcollins]

Mariner,
I friend of mine mentioned parachutes that you can tie to your stern to slow down your troll speed. Have you looked into them?

[Mariner]

A very large sea anchor might work, but it would probably interfere with the trolling lines.

A friend of mine who is used to fishing on smaller boats (under 20') suggested a bucket hung off the stern. I just laughed and explained that I have a 22" diameter propeller and I didn't see how a 5 gallon bucket would even make a dent in the boat's speed.

[digitrade]

I would not hesitate getting a trolling valve. I fish my 28TE extensively and a trolling valve is a simple and relatively (in boat terms) inexpensive way to contol speed. It could be as little as $800.

The valve gives infinite settings for prop speed.

However, not all transmissions can accomodate the valve. I purchased my 28TE new in 2000 with a velvet drive transmission. The velvet drive cannot accomodate a trolling valve so had to replace the transmission to ZF. That did make it expensive but I made the change when I repowered at 2100 hours and sold the Velvet Drive.

I would call the factory about your particular transmission if you have any doubt.

With the trolling valve you do need to change oil and filter regularly.

[Mariner]

I think I will look into a trolling valve. We have a ZF transmission, but I'm not sure the exact model number. I'll crawl down there and look some time this week then call up ZF and see what the options are. If it's really that inexpensive, it might be a good option.

I'd still love it if I could install a diesel or AC electrical outboard. The next best option might be one of the hydraulic driven drives that run off the generator. But none of these are going to happen this year, so I'll file it away under the "someday" category.

[DBM]

both me father & brother have trolling valves and they work great. My dad has a ZF transmission so one is probalbly available. I can't justify the expense on my 20' Shamrock, so i've gone to using see two sea anchors on the midship cleats. it works ok, but it was better than draging a 5 gallon bucket around. It kept fouling my lines.

DBM
Liberty