Engine down towing a dinghy?

[PuraVidaBob]

I've been towing our dinghy more during short hops & have always kept the engine up, however I've seen some boaters towing with the engine down. Is that for better tracking? It would seem to increase drag. Is there any accepted wisdom on this?

 

[slowgoesit]

I've seen both. Engine down reduced some fishtailing, and also lowers the center of gravity slightly, but runs the risk of picking up kelp, etc.
Try both ways, and do whatever works best for you!

 

[Blissboat]

I have also seen both, but usually the outboard is trimmed up to reduce drag and to avoid fouling the lower unit on seaweed, etc. or striking an object.

I always tow with the motor up, but I wonder of the weight of the lower unit sticking out at angle torques the transom. That's one reason why, when I tow a dinghy for any significant distance, like an overnight passage, I remove the motor and take it aboard. The other reason is that if trouble develops involving the dinghy, at least I'm not risking loss of the motor as well.

 

[kthoennes]

Funny you should ask this question at the moment. Last weekend we were running in some pretty high waves and had the dinghy's bridle set just close enough that it rode our wake wave, pointed generally nose up. The angle was so sharp that I thought i had left the engine down so we idled down while I checked. No, it was up. I've just never thought it was a good idea to run with the engine down (1) because it increases drag just as you mentioned, and (2) puts a little more strain on the bridle rings. Third, if we're doing very long runs we'll toss it up over the bow rail and carry it upside down and put the outboard on a bracket, but when we're too lazy for that, I'd rather not have the dinghy prop trailing in the water, pulling on the dinghy transom and maybe loosening up the outboard mounting screws or wearing on the bracket. Maybe that's all very unlikely but that's our habit.

 

[psneeld]

No problem with leaving the motor down, towed many a vessel that way.

Yes down improves tracking if motor is straight and remains that way.
No...the motor doesn't have to be down ALL the way, just enough to help (if you need to help tracking).

With some dink and motor combos....with the motor all the way up, it becomes very unstable and will flip easily.

 

[MYTraveler]

It is my understanding, possibly incorrect, that for some outboards, depending on design, water will flow through the cooling passages, to the exhaust where it can flow backward into past any open exhaust valve and into the cooling chamber. I know for certain that this is a risk with Yamaha wave runners.

 

[psneeld]

PWCs are a far cry from outboards. Maybe at pretty high speeds water could get up an outboards cooling system but never heard of a warning against it in the assistance tow business...yet we had plenty of warnings about PWCs.

As usual, check the manual or check with the manufacturer or VERY competent dealer.

 

[Cigatoo]

We run 2 separate dingy painters for redundancy and tracking. One painter from each stern hawse pipe. Motor is up. Painters are poly so they don't sink. 8'6" aluminum RIB with 100 lb outboard. At the blistering speed of 7.5 kts. the dingy tracks nice and straight on up hill side of 2nd stern wave.
Seems that having the motor down would create a lot of unnecessary drag?

 

[MYTraveler]

PWCs are a far cry from outboards. Maybe at pretty high speeds water could get up an outboards cooling system but never heard of a warning against it . . .

I don't doubt that you are right -- I just wanted the OP to be aware of the possibility, since the consequences could be catastrophic.

 

[psneeld]

I don't doubt that you are right -- I just wanted the OP to be aware of the possibility, since the consequences could be catastrophic.

Good to point out.

When in doubt, know your equipment....using all info back to manufacturer engineering department if able to.

But I have yet to hear that it is an issue.... knock on wood.

 

[guy with a boat]

Good points raised so far. The best answer varies by tender and equipment.

If your tender tracks well with the engine up, you probably don’t need to mess with it. Sometimes the tender will wander or slide around, especially in rougher water, and lowering the engine a bit helps it track. Lowering it all the way down probably isn’t necessary and increases the drag by a fair amount. Experiment with lowering it part way and see how it tows. We tow a larger tender and ours tows best with the bottom of the lower unit in the water, but only a small part of the prop. That makes a noticeable difference in tracking.

As mentioned, it is important to lock the engine straight if you lower it. Otherwise, it will work its way to one side or another, likely in bumpy water, and the tender does bad things being towed with the engine steering it one way. Usually locking the steering wheel or tiller with bungees or other method will do it. If the tender is larger and has hydraulic steering, there are clips available for towing a boat on a trailer that will do a good job of locking the engine in the center.

 

[DPKCK]

I've been towing for about 13 years, typically at 18-19 kts, with 2 different RIBs (11ft RIB w/25hp Tohatsu and 12ft RIB w/30hp Yamaha) and found that towing with the motor completely down is best for tracking and stability. Leaving only a portion of the lower unit in the water caused the bow of the RIB to porpoise up and down. Towed thousands of miles over the years this way and never had a problem. Of course, your results may vary.

 

[Simi 60]

Engine down for us
4.3m aluminium wide body dory with 30hp

 

[Osprey69]

We did lose a prop doing that once...

 

[psneeld]

We did lose a prop doing that once...

Then you may have lost it just using the dink...hard to blame towing.

 

[Osprey69]

Then you may have lost it just using the dink...hard to blame towing.

Well the force of the water took the prop off. Was it ill fit on a new motor? Maybe. Do I need to find out if it will happen again? Nope.

 

[psneeld]

Well the force of the water took the prop off. Was it ill fit on a new motor? Maybe. Do I need to find out if it will happen again? Nope.

First time you put it in reverse the same thing would have happened unless it was a 360 deg steering motor.

I just don't see towing as the culprit.

 

[Osprey69]

In retrospect it was. Little 2 1/2 sumtin' with a 360 deg. Never thought it would be designed so it would lose a prop being towed.

 

[psneeld]

In retrospect it was. Little 2 1/2 sumtin' with a 360 deg. Never thought it would be designed so it would lose a prop being towed.

It wasn't designed that way and someone along the way dropped the ball on proper inspection of a cotter pin.

TOWING was NOT the problem.

Boaters shouldn't be afraid to tow.

With proper procedures and maintenance it is usually no big deal unless you tow in open seas weather and get caught in more than expected for some reason, which often is not solely because of the forecast.

 

[kthoennes]

Well, you can think whatever you want, but I'll continue to tow the dinghy on a good bridle with the engine up. I'm not in the mood to strain my towing rings on the dinghy even more, or accumulate seaweed on the dinghy prop, or cause premature wear on the dinghy's transom attachment points, or worry that my outboard propeller cotter pin diligence was lacking.

 

[Simi 60]

What extra load?
Outboard leg is not locked down, it tilts up if any sort of load.
Prop freewheels.

 

[boomerang]

Our RIB motor has one of those stabilization fins bolted to the anti-cavitation plate so ,when we do tow, which isn't often, I leave the motor up. I don't know if it's a good idea or not but I figure that the large foil would have some kind of an effect, so it stays up. Plus the fiberglass bottom, with a little deadrise incorporated into it, seems to keep the tow tracking straight anyway.

 

[psneeld]

Well, you can think whatever you want, but I'll continue to tow the dinghy on a good bridle with the engine up. I'm not in the mood to strain my towing rings on the dinghy even more, or accumulate seaweed on the dinghy prop, or cause premature wear on the dinghy's transom attachment points, or worry that my outboard propeller cotter pin diligence was lacking.

I think the point is if your dingy tows fine with the engine completely up...great.

If it doesn't, just lower it enough to help straighten it out.

After 14 year of assistance towing almost every outboard combo out there, the engine up causes more stress on the transom (leverage).

Yawing to the end of the tow line with abrupt direction change probably causes greater wear on hardware than a nice straight tow.

With just a part of the skeg in for directional control and at a pretty good angle it doesn't pick up much garbage on it.

As for the prop falling off, not even on my list of towing problems, neither is getting hit by meteorites.

 

[boomerang]

I think the point is if your dingy tows fine with the engine completely up...great.

If it doesn't, just lower it enough to help straighten it out.

After 14 year of assistance towing almost every outboard combo out there, the engine up causes more stress on the transom (leverage).

Yawing to the end of the tow line with abrupt direction change probably causes greater wear on hardware than a nice straight tow.

With just a part of the skeg in for directional control and at a pretty good angle it doesn't pick up much garbage on it.

As for the prop falling off, not even on my list of towing problems, neither is getting hit by meteorites.

I haven't thought about the transom stress. Good point. As I mentioned, we rarely tow, unless it's just a short jaunt to another anchorage

 

[psneeld]

Our RIB motor has one of those stabilization fins bolted to the anti-cavitation plate so ,when we do tow, which isn't often, I leave the motor up. I don't know if it's a good idea or not but I figure that the large foil would have some kind of an effect, so it stays up. Plus the fiberglass bottom, with a little deadrise incorporated into it, seems to keep the tow tracking straight anyway.

Boats that are stern heavy by nature or loaded that way will track pretty well, bow heavy boats don't and bow heavy cat hulls can be almost uncontrollable.

Fins do present a larger drag problem if not completely down or nearly completely out of the water as your towing speed increases. With a bit of the skeg just barely touching the water to help with tracking if needed, if it does get rough unexpectedly, it could be a problem if towing. At that point, full up could be just as hard on the engine if dipping in the waves so I would probably lower it all the way if I couldn't get it back on board.

 

[psneeld]

I haven't thought about the transom stress. Good point. As I mentioned, we rarely tow, unless it's just a short jaunt to another anchorage

For me it was all about the day..... a high confidence in a calm weather day usually helped me make up my mind.

When anchoring out everyday in the keys and using the dink everyday..... and all the protected water....that's where I towed the most (if the weather was bad enough not to tow, I wasn't moving anyway)

The other places were the 100+ miles of Indian River in Florida, or like you said if it was a short day in the Georgia ICW where there wasn't a lot of traffic or bridge delays and going from anchorage to anchorage.

 

[PuraVidaBob]

Thanks for all the responses. I will experiment with some of the good suggestions provided. I appreciate you sharing your experiences. As often heard, results may vary based on conditions. Be safe out there!

 

[Shrew]

We tow our 13 foot whaler with the engine tilted down just a little. Just enough so the skeg and part of the drive is in the water when it gets towed.

This helps with tracking.

 

[RickyD]

Boats that are stern heavy by nature or loaded that way will track pretty well, bow heavy boats don't and bow heavy cat hulls can be almost uncontrollable.

Fins do present a larger drag problem if not completely down or nearly completely out of the water as your towing speed increases. With a bit of the skeg just barely touching the water to help with tracking if needed, if it does get rough unexpectedly, it could be a problem if towing. At that point, full up could be just as hard on the engine if dipping in the waves so I would probably lower it all the way if I couldn't get it back on board.

I always tow my dinghy unless i don’t plan to use it. Always all up with the locking lever in position. It is a Honda 40 4 stroke so no chance to bring aboard. Once, the swell got big along with wind waves and I snapped my tow line. I wonder now if my anti ventilation/cavitation fin caught and stressed the line. I have since gone to heavier line.