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Towing a dinghy at high speeds
- Thread starter Professional Hobbyist
- Start date
Prfofessional Hobyist:
Regarding the "fixed" tow method, I'd strongly recommend against it for reasons cited in the other responses AND, especially, the importance of having both vessel and dinghy/skiff/towed boat ride in SYNC with the swells—especially when running downwind in heavy swells.
When I retired in 1990 I had over 30,000 logged miles in sailing auxilliaries (at speeds averaging 5± knots) from Nova Scotia to the Virgin Islands. Since then I've added perhaps another 30 to 50,000 miles in my various power boats and commercial taxi/tour/tow operations here on the coast of DownEast Maine Usually at speeds running 8 to 16 knots). -- And perhaps 80% of above time towing a work skiff or dinghy (both hard-chined and round-bottomed.
The rule of thumb has always been to tow the dinghy on the BACK of the second stern wave behind the boat in normal conditions and when running downwind in 30-40+ knots with perhaps 12 to 20 foot ocean swells I've tended to run her on the back of the THIRD wave astern. Towing ONE wave back you face a real risk of having the tender/skiff/dinghy literally be thrown into the cockpit if you have a heavy following sea and are occasionally backing down to 'meet' the following and on-coming stern swell! (With a C-Dory this risk is exacerbated due to the outboard motor(s)....!
Additionally, position of the towing eye/ring is absolutely critical! Too high on the dinghy and you'll pull the bow down at speed (if she's not riding on the back of the second stern wave) and risk having the bow bury, dinghy fill, and either deck cleat or towing eye pulled out by what's now become an enormous sea anchor ! With the towing eye mounted too low you will experience—even in flat conditions—a damned nasty 'fishtailing' motion that can cause the dinghy to flip over (especially round-bottomed dinghys....)
Towing just one wave back can often get you a swamped dinghy and, if your painter is of inadequate size and not laid NYLON you risk snapping the painter and basically loosing the tender (or pulling out a deck cleat or towing eye)! (Ever try to retrieve/empty/load a tender even in little 5 footers?? Orthopedic surgeons would love to have you as a patient.... ( : >)
Your idea, while probably OK in a flat calm situation, would certainly "work" (with the added advantage of reducing the tender's wetted surface and, consequently, 'drag...'). With following or crossing waves the skewing and highly leveraged forces generated on your fixed gear would/will be enormous! Your chance of ripping out an anchor point and/or having the tender slammed literally sideways into the back of one of the outboards is highly probable with any significant following sea(s).
Obviously, in any towing situation, take out the oars, oarlocks, o/b kicker, bailers, cushions, shore boots, small anchor, flares, h/b compass, and pfd's, etc. unless you like to buy new ones frequently.....
Sounds like a lot of work leading to expensive problems UNLESS you use the system only for towing at very moderate speeds in flat calm waters....
Sorry for the negative input and please don't kill the messenger....
Best regards, Wes Shaw, Winter Harbor, Maine, Harbormaster and USCG 100-ton Oceans Licensed Master.
Regarding the "fixed" tow method, I'd strongly recommend against it for reasons cited in the other responses AND, especially, the importance of having both vessel and dinghy/skiff/towed boat ride in SYNC with the swells—especially when running downwind in heavy swells.
When I retired in 1990 I had over 30,000 logged miles in sailing auxilliaries (at speeds averaging 5± knots) from Nova Scotia to the Virgin Islands. Since then I've added perhaps another 30 to 50,000 miles in my various power boats and commercial taxi/tour/tow operations here on the coast of DownEast Maine Usually at speeds running 8 to 16 knots). -- And perhaps 80% of above time towing a work skiff or dinghy (both hard-chined and round-bottomed.
The rule of thumb has always been to tow the dinghy on the BACK of the second stern wave behind the boat in normal conditions and when running downwind in 30-40+ knots with perhaps 12 to 20 foot ocean swells I've tended to run her on the back of the THIRD wave astern. Towing ONE wave back you face a real risk of having the tender/skiff/dinghy literally be thrown into the cockpit if you have a heavy following sea and are occasionally backing down to 'meet' the following and on-coming stern swell! (With a C-Dory this risk is exacerbated due to the outboard motor(s)....!
Additionally, position of the towing eye/ring is absolutely critical! Too high on the dinghy and you'll pull the bow down at speed (if she's not riding on the back of the second stern wave) and risk having the bow bury, dinghy fill, and either deck cleat or towing eye pulled out by what's now become an enormous sea anchor ! With the towing eye mounted too low you will experience—even in flat conditions—a damned nasty 'fishtailing' motion that can cause the dinghy to flip over (especially round-bottomed dinghys....)
Towing just one wave back can often get you a swamped dinghy and, if your painter is of inadequate size and not laid NYLON you risk snapping the painter and basically loosing the tender (or pulling out a deck cleat or towing eye)! (Ever try to retrieve/empty/load a tender even in little 5 footers?? Orthopedic surgeons would love to have you as a patient.... ( : >)
Your idea, while probably OK in a flat calm situation, would certainly "work" (with the added advantage of reducing the tender's wetted surface and, consequently, 'drag...'). With following or crossing waves the skewing and highly leveraged forces generated on your fixed gear would/will be enormous! Your chance of ripping out an anchor point and/or having the tender slammed literally sideways into the back of one of the outboards is highly probable with any significant following sea(s).
Obviously, in any towing situation, take out the oars, oarlocks, o/b kicker, bailers, cushions, shore boots, small anchor, flares, h/b compass, and pfd's, etc. unless you like to buy new ones frequently.....
Sounds like a lot of work leading to expensive problems UNLESS you use the system only for towing at very moderate speeds in flat calm waters....
Sorry for the negative input and please don't kill the messenger....
Best regards, Wes Shaw, Winter Harbor, Maine, Harbormaster and USCG 100-ton Oceans Licensed Master.
This has been my experience as well. When you get the dinghy back on the second wave you then start "fine tuning" to find the sweet spot. When you find it you can hold the painter with one hand. If you haven't found it you get severe rope burns, or worse. But this only works in stable conditions. I have done it in some very big swells in the straits but they were ocean swells that weren't being fed by high winds. And the sea anchor effect is there at predictable periods with each swell. My Avon is a 2.85 M and is pretty small but it generates some terrific forces. It will definitely affect a C-Dory.
Dear Lloyds...
Totally agree with you re. the 'sweet spot' on back of second stern wave and had to chuckle when you mention the rope burns.... I always take a turn around a stern cleat or post and pay her out slowly... I bring her in a bit, if necessary, by milking the standing portion of the line and taking up on the slack working end inboard of the cleat. For 25+ years my work skiff of choice was a Sturdee 12' (f/g copy of Amesbury Dory and made for decades in RI) with 9.9 o/b that I towed to land passengers/tourists/owners on islands, etc.. As I recall she weighed around 350± lbs. with motor but never gave me a single problem as long as I kept her on the back of the second stern wave... (In the 20 years of servicing Great Duck Island's only private cottage 10 miles offshore, that skiff was often loaded to the gunnels with sacrete bags, water jugs, kero jugs, 2 X's, etc., etc. and probably went well over 1000 lbs... Nary a problem with her on the back of the 2nd wave...)
Best, Wes Shaw
Totally agree with you re. the 'sweet spot' on back of second stern wave and had to chuckle when you mention the rope burns.... I always take a turn around a stern cleat or post and pay her out slowly... I bring her in a bit, if necessary, by milking the standing portion of the line and taking up on the slack working end inboard of the cleat. For 25+ years my work skiff of choice was a Sturdee 12' (f/g copy of Amesbury Dory and made for decades in RI) with 9.9 o/b that I towed to land passengers/tourists/owners on islands, etc.. As I recall she weighed around 350± lbs. with motor but never gave me a single problem as long as I kept her on the back of the second stern wave... (In the 20 years of servicing Great Duck Island's only private cottage 10 miles offshore, that skiff was often loaded to the gunnels with sacrete bags, water jugs, kero jugs, 2 X's, etc., etc. and probably went well over 1000 lbs... Nary a problem with her on the back of the 2nd wave...)
Best, Wes Shaw
I have been looking at wake photos, and trying to figure out how far back that second wave is. Maybe I need to be out on the boat to see it but from here I have not figured it out. Roughly, how far back are we talking, 2 boat lengths or so? or more? I remember seeing the sailboats with the dingy out a l o n g w a y s. How far back are we talking there?
Towing the dingy will be new to us. Probably prefer having it up top.
Harvey
SleepyC :moon
Towing the dingy will be new to us. Probably prefer having it up top.
Harvey
SleepyC :moon
hardee said:I have been looking at wake photos, and trying to figure out how far back that second wave is. Maybe I need to be out on the boat to see it but from here I have not figured it out. Roughly, how far back are we talking, 2 boat lengths or so? or more? I remember seeing the sailboats with the dingy out a l o n g w a y s. How far back are we talking there?
Towing the dingy will be new to us. Probably prefer having it up top.
Harvey... When you're on board and under way the first, second, and third stern waves will be quite evident... With someone else at the helm or on autopilot just go back and, with a turn around a stern cleat or bit pay her out slowly to the top of the second wave and then just maybe a wee bit back... With your hand on the towing painter and 'milking' up just a bit you'll feel the reduced drag as you let her slightly back of the second wave crest... (The 'sweet spot' the other gent mentioned.
How far back depends on your type of boat and speed... Displacement (sailing boats you mention) often have a larger wave system with greater period... 1.34 times the square root of the waterline length along the hull.) Also, when running downwind in heavy stuff under sail you run a significant risk of the dinghy shooting aboard or into the stern if it's on the top of the first (and perhaps cresting) wave astern! Remember that the displacement sailboat (depending on size and length) will only be making 4 to 8 ± knots and the cresting wave/swell will usually be overtaking you...
Your question also reminds me that once you've payed out the proper length at a given towing speed AND THEN, after a bit or to meet or surf a swell, you CHANGE speed, ALWAYS look back and observe the dinghy or skiff. The stern wave system period will change when you change speed. (Again, type of craft will dictate how much...). If you've been towing comfortably downwind at, say 8 to 10 knots and you make a significant speed change you may well look back and find the skiff surfing down the swell and ready to bury its bow and/or riding way on the back of the back of same and serving as a sea anchor/drag. This will cost miles per gallon but you may well WANT it to create significant drag to help you deal with a difficult seas situation....
I generally use a 3/8" or 7/16" NYLON tow line (Not poly or dacron) because you want the STRETCH of the nylon to ameliorate any sudden yank on the towing cleat or bit and/or the skiff's towing eye, ring, u-bolt, etc. My tow lines for skiffs/dinghys, etc. are all between 70 and 100 feet minimum (although I'm usually not using it all).
Hope this helps.... Capn. Wes