Towing the tender

[jmcj]

After many years enjoying the sweetness and peaceful rowing of our very tender dinghy, I’ve plunged and purchased a 9’6” RIB with a 6 hp motor. Total weight will be about 180lbs. Allowing for the additional weight of a Weaver lever transom motor fitting. My question relates to the towing apparatus. I plan to use floating line throughout and was thinking of poly steel which is very strong, and easy to splice. The idea is to have a 3 line bridle at the the bow using snap hooks. Very approximately because I know there will be fine tuning, what do people thing the length of the rode would be. If you don’t like poly steel what are the preferences?

My main question has to do with the bridle at the towing vessel transom. Many years ago on this forum I remember a member describing an arrangement which made made sense and I’m wondering

[GB42-267]

I have a tow bridle rigged up as the attached photos. It basically consist of a 5/8" three strand hard laid nylon line with an eye splice on each end, hooked over the aft Port & Stbd cleats. The center have a small eye for a snap hook for the tow line, which is shortened significantly in close quarters as the second photo shows where I'm coming out from the Swinomish Channel. Also make sure the bridle isn't hanging over the swim platform and in the water. When setting the hook and backing down make sure to also shorten the tow line, even a floating line can be sucked in the props. I did have to go for a dive a few years ago because I had a bit more line floating behind than I should have and I can relate to the old saying: "Freezing the Balls Off a Brass Monkey".
The tow line is 5/8" Polypropylene and will float. The dinghy have another short bridle to avoid a side to side surge since I don't thrust the bow eyelet.

[jmcj]

Thanks Bjorn. That looks easy to do.

[2Bucks]

I towed my 11' rib w/25hp Merc with this line a couple years ago before I built my davits. Important for me was the compact and easy to store reel it comes on. 5000 pound strength was plenty for the task. I bought the yellow which made more than one person question my choice since it looks just like regular yellow poly line with a breaking strength of about 1200 pounds.

https://www.amazon.com/gp/product/B01AODJ4XG/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

[Bernie Tresner]

I have a 12' AB RIB with a 40hp Yamaha that I tow behind our 32GB. I had them made by a company in Canby, OR. The company is TOP-KNOT. I had it made with a towing bridle to keep it centered behind the boat. They come in a variety of colors and are made to order. Very Reasonably price. and their work is excellent.

Their phone number is 1-500-867-5688
website is www.mooringlines.com
No affiliation

[jmcj]

Thanks Bernie. I will give it a look.

[FrugalWife]

I have always towed a dinghy and have not bothered with float line or towing bridles. Behind the GB, I've towed a 9'6" Zodiac w/9.9hp 4-stroke, an 10ft traditional flat bottom fiberglass rowboat, and a 11ft wooden fisherman's punt. All have towed very well & straight on a single line from the centerline of the boat. I have a jam cleat mounted on the toe rail along with a cleat through-bolted to the inside of the bulwark. The jam cleat gives you a real simple way to shorten line coming into a harbor or working close to a dock. I have the towline spliced to the cleat to prevent any runaway situation. On the center stantion I've mounted a small bronze hanger that holds the towline coiled when it's not in use. At the dinghy end is a stainless snap with a strong spring closure. I use 3/8" dacron line about 60ft long for towing as it doesn't stretch much and is pretty durable ... it has never snapped regardless of the weather although I replace it about every 5-6 years and have never had a snap failure either. I've used this method on every slow boat (trawler) I've owned over the last 30+ years.

Unfortunately, I don't have any really good pics of this set-up although if there's interest I have to uncover the boat for an upcoming survey so could take some pics.

[JP]

Jim, to answer your earlier question, we have used a tow set up like what you described for nearly 20 years with a 17ft Arima with 115 HP Merc. (This is the workboat!!). It consists of the short line you mentioned and a long towline of up to 100 ft. However, the short line does not have the heavy steel ring you mentioned. Instead, we use a spliced-in stainless thimble (allows slip adjustment and less friction on the "working" towline) of appropriate size for 3/4 line. The towline and the short line are simply 3/4 braided nylon, as in anchor line, with a few net floats on it in case we ever need to pick it up. (Proper sizing depends on the job you want it to do.) The performance numbers are more than adequate for our application. The end of the towline has a spliced in galvanized thimble, to a galv shackle, to a 4 or 5 inch SS snap hook. Both the short and long lines are adjusted in length for the prevailing conditions and various boat speeds. We usually want it on center-line, riding slightly "downhill" on the second stern wave. That 2nd wave distance astern fluctuates with power setting, so adjustment capability is a must. This arrangement, according to my professional rigging engineer friend, carries only about 1/3 of the towing load on the short line (starboard cleat) and 2/3 load on the towing line, (port cleat). The towline also has some stretch to it, intentionally. Eventually, (years and years) the towline gets tired and looses the stretch and needs replacement, (once or twice in 19 years). (The risk in a non-stretch line is straightening out the snaphook and dropping the tow. Have seen it happen many times.)
We tow at 1600 to 1800 on the RPMs at 8.7 to 9.5 knots. The 1600 setting is the sweet spot for long cruising as it creates less stretch and wear on the gear. As you know, anywhere from home to Icy Strait, AK and back, one can find all kinds of weather and conditions. That said, we have never had what I would call an uncomfortable event with this set up. (I do confess to forgetting to re-cleat the short line or the towline when leaving a dock after using a cleat for a dock line. Can be embarrassing!) Normally, (90%?) the towline is out about 50 ft astern, or wherever that 2nd wave is. In very rough weather (10%?) it is adjusted out full length for easier towing. Chafe guards will give the lines longer life and I made up my own until discovering Chafe Pro; an absolutely superb product, (bought a spare pair several years ago and they are still unopened)! We NEVER EVER adjust the tow when under tension. Always in neutral with little way on.
Towline can be let out and recovered from the aft deck or the swim step. When recovering, (little or no way on) I throw on a life vest and prefer the swim step (unless in rough water). It is easily coiled on the step and it stays out of the way right there. (Fortunately, we have the wide swim step.)
Sorry this turned out so long. Hope it helps.
Jp