Dinghy and motor choice

Sailm8 · Mar 10, 2017

Some considerations:
1. Towed or davits? Does a little drag bother you? Do you already have davits?
2. How far do you dinghy in to a dock? I have a 5hp Tohatsu and it takes 40 - 50 minutes to go 3 miles. Many times I wish I had a 10hp when the weather looks bad. You can always go slower with a larger motor. Install a motor crane if the motor weight is a problem. On davits you can leave the motor on (mostly).
3. We have a 10ft mercury RIB and carry an umbrella, beach bag, cooler, 3 gallon fuel tank and 2 beach chairs. We spend a lot of time at various beaches and are willing to travel a fair distance. Our dink is crowded but just right for two people.
4. Hyperlon (sp) for summer sun.
My dink weighs 110 and the motor about 60lbs. I tow the dink and use a crane on the motor.
5. Make sure the motor has a shift for reverse. Comes in handy.

Gunni · Mar 10, 2017

Just got back from some open ocean trade wind sailing in the Lesser Antilles; a 5 HP motor can move a boat and 3 three people in flat water, but in 25kts and chop you will have a wet slow chug. A 5 HP motor will not plane a boat. A planing boat is a safe boat. So you will move at maybe 5 kts in optimum conditions.

You can tow a RIB easily in nearly any conditions. Get a motor lift, minimum 10hp motor and be prepared to ship the motor during open water rough conditions, otherwise tow it motor and all on a thick polypropylene tow line of 30 ft.

TommmD · Mar 10, 2017

I use a 10ft air floor Walker Bay with a 6HP Tohatsu. Will plane with me alone, plenty of room for 3 plus gear. The boat is light (~60 lbs dry) I do haul it up on davits, complete. Getting the motor off is more than I would want to deal with. You have to gauge what you're willing to spend vs the (expected) life of the dinghy. I'm in New England so the life of a PVC boat is going to be different than Fla. Since I'm predominately a w/e boater, I cover mine during the week to extend it's life. Its a pain, but its always dry when I get there.

SEMPERAVANTI41 · Mar 10, 2017

I would look into davits first if you don't have them. I would try to get the largest dingy and motor you can comfortably handle. When you decide check out Buster's Marine in Brooklyn, NY. I purchased 2 Mercury hardbottoms from them, they have the best prices on dinghys. Check out OnlineOutboard for a Tohatsu outboard.

thinwater · Mar 10, 2017

I've had a 3.5hp on a 9.5' dinghy for 1 years. It will plane one person and slog with more. Very light. If I did not have davits I would sell the dinghy and use kayaks; I'm not a believer in towing, and lifting on deck is absurd to me.

How often would I like to plane?
* Most harbors or coves are either no-wake zones, speed limit zones, or morally should be. Even though I can zip when alone, I don't because I consider it rude and adolescent if there are other boats, marinas, or docks around. Do we like PWC zooming about? No we do not, and fast dinghies are the same thing.
* I very seldom use a dinghy in rough water. I avoid anchoring in those places for other reasons.
*Unless the boat is an RIB with considerable V to the hull (and I do not think that is what the OP is considering), planing on rough water will shake your teeth loose. Calling it safer in a flat bottom boat is curious.

Without davits I would not consider an RIB. Will I get an RIB next time? I don't think so. Even though it is the fashion and is well proven in many areas, I don't think it suits my needs.

Captain Larry-DH · Mar 10, 2017

Thinwater has it right.

Not safe to plane in chop, and not nice (or legal) in inner harbors.
Towing is not safe or wise in open water, especially when the wind is up.
Handling a motor that requires you to use a crane is a PITA. Just because you can lift it, doesn't mean you don't need a crane to mount/dismount the motor safely (while the dinghy moves around next to the larger boat).
Unless you have davits, you will mount/dismount the motor in every new harbor, but you won't want to (or need to) plane in every harbor.

I changed from a 59# (9.8 HP Tohatsu outboard that would plane) to a 30# (2.5 HP Suzuki outboard that won't plane) and it's MUCH easier to mount/dismount the motor. I kept my 9.8 just in case I changed my mind about the "rinky dink" Suzuki. The 9.8 is smoother, quieter, has a reverse gear and shallow water drive position, and can plane the dinghy. I use a block of wood to partially tilt the 2.5HP motor in shallow water, and have to spin it 180 degrees for reverse, but still don't plan on using the 9.8 again in the foreseeable future. It sits in my basement, as a spare.

PS - I recommend TruFuel with these small 4-stroke motors, to avoid carb gumming a fuel related problems. They sip fuel so the price is not an issue.

DougM · Mar 10, 2017

My choice was a 10' Zodiac air floor rollup. Easy to stow in a lazarette when deflated, and can be hoisted aboard easily. Power is an 8hpYamaha 4 cycle, which admittedly is a bit heavy. All that aside, its quiet, easy starting, and will plane the dink easily. Engine is stored on a rail mount, and handled with a Forespar hoist which also stores in the Lazarette when not needed.

shemandr · Mar 10, 2017

It is very nice to have neutral if not reverse. With neutral you can warm the motor up before casting off.

LeslieTroyer · Mar 10, 2017

shemandr said:
It is very nice to have neutral if not reverse. With neutral you can warm the motor up before casting off.

a lot of the smaller motors without shifters, have a centrifugal clutch - so as long as you are warming up at idle - the prop isn't spinning.

Captain Larry-DH · Mar 10, 2017

LeslieTroyer said:
a lot of the smaller motors without shifters, have a centrifugal clutch - so as long as you are warming up at idle - the prop isn't spinning.

Just the Honda 2.4 has the centrifugal clutch. The Suzuki is about one pound heavier and has a shifter for F/N. I think all the other 2-3.5 motors have F/N. Some of the heavier ones at 4HP+ have F/N/R.

shemandr · Mar 10, 2017

I don't want to dwell on this but I have a Nissan 3.5 with no F/N. A friend has a another brand 3.5 with F/N but the shifter doesn't work very well. When I complain that I don't have the F/N, he says it works as good as his.

njlarry · Mar 10, 2017

Lot's of good discussion here on dinks and motors. All points well taken. As a new,one season dink user I'll add my 2 cents. I choose a 9.5? footer with an air floor, from wm with a 2.4 air cooled honda. When using it I feel the 10.4? would have been a better choice but when lifting, storing, towing and docking ( all types of use too) I am glad I picked the smaller model. There was no real cost difference but the 9.5 easily carries four and is difficult enough to man handle. The honda came with our o'day and has very low maintenance needs but it is noisy. The worst is the centrifugal clutch. To start it requires advancing the throttle which means it wants to take off like a rocket the instant it catches.
This season I will be considering a 4 to 6 hp engine with a clutch. Likely the 6 as the 4,5 and 6 all weight the same. We can haul the dink aboard if the weather gets nasty but usually tow with the honda on it. More experience sailors in our marina have towed many miles with out any problems leaving the motor attached. If I had davits and a bigger boat I would consider a rib but for us the air floor has worked well.

RoyS · Mar 11, 2017

Since when have sailors been in a hurry? We use a 2.5 HP Yamaha on our tiny rollup. We never get out of a fast idle when going to or from shore. Our motor is a four cycle which means no oil and gas mixing. Also recommend non-ethanol gas. We use less than a gallon of fuel a year. Tow with motor all the time. Use halyard to place dinghy with motor attached on the bow when leaving boat for extended time in a marina. Hauling it up on deck with halyard is a one man job. Recommend smaller and lighter choices.

BigEasy · Mar 11, 2017

Just sold new 6HP Yamaha and purchased a 2.5 Suzuki. At half the weight (29lbs) I can easily handle it without using an outboard hoist. I only use it and the West Marine compact rib occasionally; so it fits my needs. If I were a full time cruiser I would opt for a bigger rig.

Captain Larry-DH · Mar 11, 2017

njlarry said:
snip
This season I will be considering a 4 to 6 hp engine with ..... snip.....We can haul the dink aboard if the weather gets nasty but usually tow with the honda on it. More experience sailors in our marina have towed many miles with out any problems leaving the motor attached. If I had davits and a bigger boat I would consider a rib but for us the air floor has worked well.

Larry,
When you're towing that dinghy with engine, the wind is 25-30 apparent, and you hit a wake there's a good chance that dinghy will go airborne and flip, especially if you add a #60+ Motor head up high on the transom. Then think about bringing it alongside and righting it in such conditions.
Even worse, imagine you're towing that dinghy and you see the wall of low black clouds from a severe summer squall line approaching fast. You have maybe 15 or 20 minutes tops before it hits you hard with (perhaps) 60+ mph gusts along with pelting rain and lightning. What do you want to be focusing on at the that point in time?

njlarry · Mar 11, 2017

I don't tow it in high winds.

On the Chesapeake in summer 10 knots is considered a stiff breeze.

Captain Larry-DH · Mar 11, 2017

Haha.

But I know you have severe t-storms.

Unfortunately LIS is almost the same in July and August. But we do have our better days when a cold front moves through, and in other months.

Gunni · Mar 11, 2017

I have towed a RIB dink many miles in 30 knot winds, open ocean. You have to know how, and you have to have the right tackle. If your boat is flying you might want to consider a RIB with a low CG.