rowing an inflatable w/out a keel: how bad is it?
- Thread starter matts997
- Start date
The keel strips do make the steerage track better, but they are not perfect. But I liked them well enough to move them from an old dinghy to my new one.
The other Gene beat me to it, I was gonna ask the same thing. Rowing our Avon is downright embarrassing if anyone is watching, and yes, a bit squirrely under motor power.
A tip: When you determine the mounting position of them, pay attention to the folding area of the dinghy so that your natural folds of the floor aren't in the middle of the fins.
The Achilles in the rowing pic I posted has gone away- My ex insisted it was HERS. Been rolled up and stored now for 7 years, unused. I built a hard dink as a replacement- would MUCH prefer the Achilles back
I have a PRU-3. It does not row well at all. Even if you get it going straight, if you then coast for 8 or 10 feet on a dead calm day, it will turn sideways, all by itself. Rowing against a 2 knot head current or a 10 knot head wind is a tough haul with little headway.
It's a great little boat for what it is intended for, which is being stored a lot & used a little. I can go from rolled up in the bag, to in the water with motor running, in just under 6 minutes, if I use a battery powered leaf blower to inflate it & then finish off the air pressure with the foot pump that comes with it. Even my silly little 21' micro-cabin boat, is able to store the PRU3 easily when it is rolled up. Actual boating performance is not that good, but it gets me by. If I needed to use it more often, I would want a hard bottom boat.
A 30# thrust trolling motor ($100) with a group 27 battery (another $100) will get you about 3 knots & go for about 45 minutes to maybe an hour if you are lucky, with 2 people in the boat & no current or wind to fight.
A 2.3 hp gas outboard moves it about 4-5 knots at 1/3-1/2 throttle unless you load it like a pig. A 3.5hp does just a little better. A short shaft outboard will cavitate badly at 1/4 throttle if you have only a single 200# person in the boat. Loaded with twice that weight, the short shaft is fine. A long shaft motor works well with lite loads, but adds stress to the transom, so I would derate the 6hp max rating if using a long shaft.
Even with the motor, the PRU3 slides sideways pretty badly if there is a cross wind. Even 5 knots is noticeable. 10 knots makes you pay attention. 15 knots makes you concentrate a little harder.
There is also the RU3, which is 2/3 the price of the PRU3 & about the same size/weight. The PRU has tubes that are an inch larger in diameter & has slightly higher HP & weight capacity written on the tag. When I bought the PRU3, I was told that the RU was PVC & the PRU was Hypalon. I now see on the website that both are listed as being PVC. I have one unconfirmed report that in the old days, the PRU was made by Achilles. Mine came from China. I've probably had it for about 3 years now. I've probably used it 15-20 times.
If I were to add a keel to the PRU, I might choose to add 2 small dagger boards on the back of the transom. It would also be nice to have a pair of wheels back there for beaching. Plastic wheels encased in a cover that mimics a dagger board might be a good way to go.
It's a great little boat for what it is intended for, which is being stored a lot & used a little. I can go from rolled up in the bag, to in the water with motor running, in just under 6 minutes, if I use a battery powered leaf blower to inflate it & then finish off the air pressure with the foot pump that comes with it. Even my silly little 21' micro-cabin boat, is able to store the PRU3 easily when it is rolled up. Actual boating performance is not that good, but it gets me by. If I needed to use it more often, I would want a hard bottom boat.
A 30# thrust trolling motor ($100) with a group 27 battery (another $100) will get you about 3 knots & go for about 45 minutes to maybe an hour if you are lucky, with 2 people in the boat & no current or wind to fight.
A 2.3 hp gas outboard moves it about 4-5 knots at 1/3-1/2 throttle unless you load it like a pig. A 3.5hp does just a little better. A short shaft outboard will cavitate badly at 1/4 throttle if you have only a single 200# person in the boat. Loaded with twice that weight, the short shaft is fine. A long shaft motor works well with lite loads, but adds stress to the transom, so I would derate the 6hp max rating if using a long shaft.
Even with the motor, the PRU3 slides sideways pretty badly if there is a cross wind. Even 5 knots is noticeable. 10 knots makes you pay attention. 15 knots makes you concentrate a little harder.
There is also the RU3, which is 2/3 the price of the PRU3 & about the same size/weight. The PRU has tubes that are an inch larger in diameter & has slightly higher HP & weight capacity written on the tag. When I bought the PRU3, I was told that the RU was PVC & the PRU was Hypalon. I now see on the website that both are listed as being PVC. I have one unconfirmed report that in the old days, the PRU was made by Achilles. Mine came from China. I've probably had it for about 3 years now. I've probably used it 15-20 times.
If I were to add a keel to the PRU, I might choose to add 2 small dagger boards on the back of the transom. It would also be nice to have a pair of wheels back there for beaching. Plastic wheels encased in a cover that mimics a dagger board might be a good way to go.
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I mounted them on the floor. See the picture I posted above in #8. I can't say why I did it this way- maybe the instructions told me to floor mount. I can't see any problem with mounting on the tubes except that when the dinghy is sitting on a hard surface, the fins will be subjected to most of the weight. But they might work better because they will be lower in the water.
Either way, when you roll up the dinghy the transom will determine the fold points and indicate the best spots to mount the fins.
Compared to my PRU3, this looks like the same tube material, twice the weight, twice the HP rating, 3-4 times the speed & probably 20% more weight carrying capacity.
I had to row my PRU3 about a quarter mile last weekend after the engine blew up. It was in a decent cross wind (~10kts) It was difficult. Then I rowed it another quarter mile back to the mooring with a dead 2.5 hp strapped to the back. A new 3.5hp in the floor, and wife and I in the back. It's very difficult to row with another person in the back 'cause you hit them with the oars.
My slip neighbor got a dink from Costco this spring (HydroForce iirc). Looksxx nice. AL floor. Bigger. Cheaper. Lots cheaper - like $500. The glued on stuff (oarlocks, rope holders, etc..) seems to be degrading in the UV kinda quickly. But he also only got 3 years out of his last WM dink 'cause he leaves it in the water behind his boat all the time.
My slip neighbor got a dink from Costco this spring (HydroForce iirc). Looksxx nice. AL floor. Bigger. Cheaper. Lots cheaper - like $500. The glued on stuff (oarlocks, rope holders, etc..) seems to be degrading in the UV kinda quickly. But he also only got 3 years out of his last WM dink 'cause he leaves it in the water behind his boat all the time.
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 21,692
So Dinghy's are now a disposable commodity. What will that do to the garbage and ocean disposal problem.
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 21,692
A number of years ago, I read a report from a research vessel that studied plastic pollution in the oceans. That report concluded that the vast majority of plastic in the oceans is in the form of raw plastic pellets that are used as feeder material to manufacture consumer goods, not the finished goods that we see in all the tree hugger propaganda.
I think these may be called plastic micropellets, at least after some weathering.
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I gave up on inflatables years ago. Can't keep the air in or the water out. I now have a Watertender 9.4, a plastic cathedral hull kind of design. A little heavy at 114# but it rows pretty well and tracks straight with the outboard and almost as stable as an inflatable. And nearly bulletproof. Best part is they're built in my home port of Muskegon, Michigan. Most of the cheaper imflatables come from China or some other Asian country.
They were the "resin pellets" that plastic goods factories buy as a raw material. The main source of them in the ocean is said to be spillage while loading & unloading bulk quantities to & from transport ships.
Unfortunately, it would seem that we are moving in that direction. The quality of the low priced Chinese stuff does not make me think of it as an example of durable goods. I'm thinking about maybe designing & building my next dink because I am not fully happy with what is available on the open market.