Towing dinghy questions

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Matt Gent
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Towing dinghy questions

Post by Matt Gent » Thu Nov 21, 2019 9:38 am

I'd like to build a small S&G dinghy for a few uses - bombing the creeks around my house, throw on the roof of the DE25 for certain trips, and maybe tow around with the DE25 in other areas. Along the lines of a GV10. It will be very light & simple, and powered by a 6hp Suzuki for now (my kicker), maybe a 20hp later.

What I'd like to learn about is towing the dinghy. I'd rather not drill holes and put in metal fasteners like a bolt eye. How should I set up the towing bridle? Would be towing on plane. Should it pull from low (like at the bottom of the bow transom) or high up near the rubrail?

Any ideas how to set up towing fixation without a bolt eye? How about epoxy potting a loop of aramid fiber rope in a loop? with lifting & handling the boat around I'd rather not have the protrusion to hang up on. How do the traditional boat builders set up a tender to be towed? If I can tow high, I can use the rubrail or a gusset in the corners of the bow transom.

Any ideas or pictures of examples?



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Re: Towing dinghy questions

Post by terrulian » Thu Nov 21, 2019 10:22 am

Although every hull shape is different, generally speaking, it is not a good idea to tow from the top of the bow. It can cause the dinghy to bury its bow in a wave, or cause it to yaw since, when it gets even slightly sideways to the tow line, you are pulling it in a way that will cause it to heel or tip, which will in turn make the hull that is touching the water to be asymetrical. In certain conditions this can even cause the dinghy to heel enough to dip its rail and take on water. A bow eye near the waterline will prevent this.
If you really object to the protrusion, which seems to be what you want to avoid, you can create a cup shape in the bow of the GV10, which has a pram bow, and then place a stainless pin recessed in the cup.
A bridle will not be necessary but if you want one, the bridle is created on the towing boat, not the one being towed.
Also, a related point is that, when approaching a dock or slowing for another reason, always shorten the painter so that it can't be sucked into the prop of the tow boat. Otherwise, adjust its length to produce the least amount of jerking when there is a bit of chop.
As to towing at planing speed, this will take some experimentation and can be somewhat scary, so work up to it.
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Re: Towing dinghy questions

Post by fallguy1000 » Thu Nov 21, 2019 10:35 am

terrulian wrote:
Thu Nov 21, 2019 10:22 am
Although every hull shape is different, generally speaking, it is not a good idea to tow from the top of the bow. It can cause the dinghy to bury its bow in a wave, or cause it to yaw since, when it gets even slightly sideways to the tow line, you are pulling it in a way that will cause it to heel or tip, which will in turn make the hull that is touching the water to be asymetrical. In certain conditions this can even cause the dinghy to heel enough to dip its rail and take on water. A bow eye near the waterline will prevent this.
If you really object to the protrusion, which seems to be what you want to avoid, you can create a cup shape in the bow of the GV10, which has a pram bow, and then place a stainless pin recessed in the cup.
A bridle will not be necessary but if you want one, the bridle is created on the towing boat, not the one being towed.
Also, a related point is that, when approaching a dock or slowing for another reason, always shorten the painter so that it can't be sucked into the prop of the tow boat. Otherwise, adjust its length to produce the least amount of jerking when there is a bit of chop.
As to towing at planing speed, this will take some experimentation and can be somewhat scary, so work up to it.
Great post.
My boat build is here -------->

viewtopic.php?f=12&t=62495

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Re: Towing dinghy questions

Post by fallguy1000 » Thu Nov 21, 2019 11:08 am

here is a good article

Oops.

http://www.boatus.com/magazine/2016/oct ... basics.asp


I think a snubber is wise and as a person who had a towed boat break off; if you are going any large distance; a gps tracking device on the dinghy is wise.

Fortunately, we realized it and were only half mile away, so could see it, but a towed dinghy is nervewracking to watch every five minutes and rather distracting..
Last edited by fallguy1000 on Thu Nov 21, 2019 1:09 pm, edited 1 time in total.
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Re: Towing dinghy questions

Post by Matt Gent » Thu Nov 21, 2019 11:30 am

Thanks for the input.

Searching around I see all kinds of setups. Bridles on both ends, no bridle, multiple eyes to tune the pitch of the tender. Motor on, motor off, motor trimmed up, motor trimmed down, drogues. Seems to depend a lot on the weight and stability of the boat in tow.

The low bow attachment made sense to me to keep it proud, but one friend indicated the dinghy will respond better if the line is out of the water instead of dragging through it.

I'm looking at under 100lb planing hull shallow-v dinghy, and mostly for short transfers between islands in smooth-ish water. Mainly to avoid hoisting it up and down to the roof.

My towing is limited to emergency low-speed trolls. I was once passed at a speed boat rally by a tunnel boat in tow at 60+mph.

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Re: Towing dinghy questions

Post by Capt UB » Thu Nov 21, 2019 12:46 pm

I can't say it enough, get a very good cover for the dink/RIB. No matter how you tow it, just one wave from a passing ship/boat could flip it.

I never did this, but painting the bottom bright orange and having the cover bright orange sure would stand out!

In the Caribbean, between the islands BIG waves can pop up and fill the dink/RIB, so check with the long term cruisers in that area or where you are sailing, how they are towing. Not the weekender cruisers.... ;)

During my Central America cruises, the small 6hp OB was mounted on the stern rail and the old 55 hp laid on deck, both chained/locked and covered. I did tow the RIB with cover, but if it got in the way I could cut the line... The dink stayed on deck, too pretty to loose.

I never liked towing with an outboard on the dink, but lifting a 150 lbs. plus OB can be back breaking and just a pain in the ass. I did always remove the OB on long runs longer then 50 miles. Anything over 100 miles, the dink was stored on deck, never liked night time towing (7 knots x 24 hours= 168 miles, at least half at night.


The RIB was so old it had more patches then origanal rubber! Still I kept it covered and transon drain plug out when towing. The work horse!
The Dink was glass and wood (mostly bright work), two people, snokling gear or supplies and 6 hp OB. Date night boat...
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Re: Towing dinghy questions

Post by terrulian » Thu Nov 21, 2019 7:54 pm

What the captain says. I wouldn't want to tow a dinghy anywhere offshore but I live on the coast of northern California where we tend to see large seas.
We had a crane for the outboard, which we kept on the stern rail, but even so, lowering it and securing it on the dinghy is not for the fainthearted in a chop.
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Re: Towing dinghy questions

Post by Chenier » Thu Nov 21, 2019 9:52 pm

Nevermind offshore - we tried towing our dink on the Chesapeake for several years. It would work for a while then get capsized and torn apart. Finally got an inflatable that we could lift onto the roof.

The only folks that I see regularly towing dinghys around here are the slower sailboats.

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Re: Towing dinghy questions

Post by joe2700 » Fri Nov 22, 2019 10:28 am

Matt Gent wrote:
Thu Nov 21, 2019 9:38 am
Any ideas how to set up towing fixation without a bolt eye? How about epoxy potting a loop of aramid fiber rope in a loop?
I wouldn't pot the rope because when it wears out it would be a pain to replace. For pointed bows I've seen people put a small but very strong tube through the bow across the boat, an inch or 2 back from the tip. Then they put dynema through that and splice it into a loop for a very strong soft bow eye.

You could cut a round hole in the flat bow, glass a fiberglass(g10) rod across the hole from the inside, then glass some sort of fiberglass bowl shape to the inside of that to stop water from getting in. That would give you a place to splice a soft eye on you flat bow without anything protruding outside. I agree with others, it should be low on the bow.

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Re: Towing dinghy questions

Post by Evan_Gatehouse » Fri Nov 22, 2019 6:44 pm

The last suggestion of a glass tube through a stem bow is fine but a S.S. U bolt is pretty chafe resistant. I towed a FB11 hundreds of miles but usually stowed it on deck because that is safer for rough water.

We would tow our GV10 for short distances with a 15 HP motor but again, it was easy to lift with a stern arch. So we did that.

Both towed well and the GV10 could be towed at planing speeds. A low point is essential.
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