Trolling Motor Suitable for Dinghy Power?

[NCC320]

I currently have a Zodiac Cadet 310 inflatable (10ft) powered with a 15 hp Evenrude which weighs 68lbs. I do not have davits or a lifting crane on my sailboat. At 71 yrs., I find lifting the motor up to it's support bracket becoming a bit difficult, especially when singlehanding. With the engine and gas tank removed, the inflatable can be stored on the fore deck and I have a spare halyard, block and tackle, and harness for the dinghy suitable for this.

I also have a seldom used battery powered trolling motor and a group 24 battery for power. This package would be easier to manhandle aboard the sailboat, and I would add a second battery so one is for standard use and one for backup so I don't get stranded. Dinghy speed would not be an issue, but ability to motor against wind and current would be an issue.

Do any of you use a trolling motor as power for your inflatable dinghy? What would be the pros and cons of doing so? Thanks.

[LakeSuperiorGeezer]

A battery would weight as much as the 15 hp and then you have a spare and the trolling motor. Go with two outboards or one small one, say four hp. The four hp is what is recommended as a minimum: Zodiac Cadet 310

[NCC320]

No doubt that a 4hp engine would be better than the trolling motor. However, I have the trolling motor and one of the two batteries already, so don't need to spend a lot of money. If it comes to spending money, a Garhauer hoist would be cheaper than a new motor, I suspect. The 15hp Evenrude weighs 68lbs., a Sears Die Hard Group 24 weighs 35 lbs., so there is a weigh savings and the batteries are more compact, and would have to be lifted only a short distance (to sailboat cockpit from the open stern). It's interesting that the link to Zodiac Cadet 310 shows minimum of 4 hp., while the dinghy comes with oars (however, I recall once on another inflatable with oars, rowing like crazy as the sailboat got further away, so the 4hp. minimum may be a sound recommendation). The trolling motor works fine on a 14 ft. jon boat (low speeds of course). Thanks for your comment. Have others tried the trolling motor approach or have an opinion?

P.S. Checked Mercury site to see what weight of a 4 hp (4 stroke) is and it is 55lbs., so it wouldn't be a big improvement over the current 15 hp 2 stroke.

The best thing might be to run some tests when the wind is kicking up a bit to see how my particular trolling motor works on this inflatable.

[sidney777]

Hello. I have used a 40 lb thrust electric trolling motor on my inflatable dink for my sailboat many times. -I have also had -2- #27 batteries. I usually use one battery but went on river trip with two. -- Used it to get to my moored sailboat in Burnham Harbor Chicago 1/4 mile. -- In ORANGE BEACH for over a mile (loaded up) to get to my sailboat in a Bayou Hurricane Hole. **If you can leave Battery in dinghy and Charge it (no lifting) ! --I have went against tides and wind at same time ! ( on river trip Chicago to Florida I saw and talked to two 27ft and 30 ft sailboaters who WERE USING THEIR ELECTRIC trolling motors for 10-20 miles because diesels broke down). More amazing; 30ft was steel. Heavy. But, not against current. Ask me questions if needed.

[centaursailor]

I have a 4 year old Bison Trolling motor that I use regularly.
Pushes the 4 man dingy along nicely. Have the original 45ah Flooded Glass Matt battery and bought a similar gel battery for backup last year. Can carry both batteries without much effort and the trolling motor is very light.
Thought the Bison was a USA trade mark but turns out it was made in China.
I also use battery power to blow up the dingy via a small electric air pump and still have plenty to of power left in the first battery to get out to my summer deep water mooring.
Have used the motor on a couple of occasions when my self and my son could,t make headway against the wind or tide with the oars.
All in all its a reliable system and never needs much attention.
Safe sailing.

[sidney777]

One more thing. It is sooo quiet, it is wonderful. Reverse is good too. Have also used #29 heavy battery and no damage to wood dinghy floor. Also used to inflate dinghy as Centaur above. --Used battery in dinghy with Davis anchor light and hooked up Depth/fishfinder for fishing. --- I think you can get TIME battery WILL last at low,med, high speed from Minkota.

[bljones]

We have an old 26 lb. thrust Minn Kota on our 7' inflatable, "Quack."
Pros: Quiet.
Light.
Reverse, which our old 3 hp gas O/B didn't have.
Weed cutting prop.

Cons: Range. At top speed, battery is 50% discharged in an hour
Speed. Even top speed isn't speedy, and cutting speed increases range, so
Power. Admittedly, it is not the highest thrust trolling motor, but at times we had trouble travelling into the wind in the harbour. I wouldn't even think about using it to travel in open water.

All in all, it has proven to be an adequate solution for us, but JUST adequate.

[SlowButSteady]

I suspect that a 35 lb group 24 battery is a starting battery, rather than deep-cycle. You definitely want a deep-cycle battery for such an application. However, you might save a bit of weight by getting a deep-cycle AGM battery; you can drain them a bit deeper than wet-cells w/o harm also.

[NCC320]

Thanks for the comments on the possibility of using a trolling motor as a low weight solution to lifting a heavy 15hp Evenrude dinghy engine.

It looks like, that where distances aren't too great and wind/current conditions aren't too strong, it is infact a workable solution, although not as good as the Evenrude in operating the dinghy (but quieter and no smoke).

I would have to buy another deep cycle battery and later replace the one I already have, and if my trolling motor doesn't have enough thrust, maybe a new trolling motor. At that point, an engine hoist davit for the Evenrude begins to look attractive (~$300 from Garhauer). I'll run a few tests with the trolling motor during this spring and then decide.

[dabnis]

NC,

I had a 2HP Honda OB on an 8 foot inflatable with a "soft" floor.
It was more than adequate with 2 people aboard against the
wind & chop. Not fast, but we could make headway with no problem.
I think it weighed about 25 lbs and burned very little fuel.
Had it for many years, bullet proof motor.

Dabnis