What Actually Happens If You Oversize The Dinghy Outboard?

[a64pilot]

I would re think the lifeboat idea though, sure if it's all you have, grab onto a seat cushion, but I would not have a Walker Bay as a lifeboat in my plans

[KISS]

Originally Posted by a64pilot

I would re think the lifeboat idea though, sure if it's all you have, grab onto a seat cushion, but I would not have a Walker Bay as a lifeboat in my plans

Well, I don't want to turn this into another "dinghy v. liferaft' thread (entertaining as those are...), but suffice it to say I lean toward the dinghy. Ideally, I'd have both. I'll definitely have the dink regardless, though, so might as well set it up as a makeshift lifeboat when offshore: even if I also have a liferaft.

[Martkimwat]

I have a Walker Bay 8 that came with the inflatable tubes already fitted as opposed to the aftermarket add-on from Walker Bay, and the placard on the stern says it is rated up to 4hp and 3 adults. Obviously the transom must be able to stand it so I guess it is more a stability issue, probably when turning. If the weight of the motor is the same then just keep the revs down and it should be fine. I have a Mariner 3.3 on the back and have never needed full throttle so I don't think it's an issue.

[Triumphant]

Originally Posted by belizesailor

Probably not an issue with just 4HP, but the transom is engineered for the rated HP. So, too much over rated HP and you can damage the transom.

Change Can to "Will damage the transom", I have seen it happen and it is an extremely difficult repair job

[coastalexplorer]

Hello.

The Walker bay 8' and 10' dinghies were designed by Mr. Graham H Shannon who formerly Did business as Avia Designs in North Vancouver.

The original 8 foot Walker bay was sold rated for 2 horse power and did not have a rib tube.

Later versions were manufactured with holes pre drilled for adding a RIV tube. These are available in two different qualities. The silver grey coloured one has a port and a starboard inflation valves. The cost is approximately $800. IF you buy this kit? It comes with a new safety placard to self adhesive over the original; which states the modified boat is now rated for 4 horsepower.

I own one of the earliest production boats, So have drilled the the holes myself & completed this modification to mine. I do believe that my weight plus my crew do overload it, but we have travelled up to 20 miles in one day checking out navigation channels through shallow bays at low tide using a two horse power British Seagull..

I Have found this RIV tube to be a life saver: So I do not understand anyone who is too cheap to buy one IF they are planing on owning a walker bay boat.

[sanibel sailor]

Originally Posted by Bluebeard

This is the most amazing nonsense I've come across in a long while.
An 8ft dinghy isn't safe anywhere other than on a model boat pond in the local park.
Been there done it.
And if the OP understands so little that he has to ask this question perhaps he should stay on the beach.

Is this a serious forum or not?

Nothing like a little dogma...

Wasn't Dougal Robertson and 5 crew adrift in the Pacific for 38 days in a rigid dink and an Redcrest?

[hpeer]

Originally Posted by KISS

So, the consensus is that 4hp should be fine, with a little common sense in using it.

Thanks all



I looked into the Pudgy: awesome piece of kit! ...But insanely $$$. I do plan to double the dink as a lifeboat (...subject for another thread). Not married to the WB 8, another make might be better. But it can't be much larger than 8, to fit where I need it (i.e. in a cockpit locker, on its side).



It will be an ~30' steel boat, ~10k lbs displacement (don't have it yet, in planning stage currently). Haven't been able to find any good information on this; all the sizing data is for people who want to do serious motoring (not just the occasional in/out of harbor). But I've found anecdotal evidence of boats of this size successfully using small outboards. E.G. The SV Atom used a 3.5hp for the purpose.



I don't follow. A lot of sailors, including circumnavigators (see SV Atom above for an example), use rigid dinghies 8' or smaller. On a 30' boat, there's no way to safely carry a RIB, and I don't want a roll-up.

KISS,
our 33' steel boat came with a nice little 7'6" dink designed to fit on th coach roof. The PO and dink builder was about 150 lb and his wife maybe 100lb. It worked for them. Not us, we had waaaay less freeboard than they did. Simply unsafe.

We now have a 10' Porte Bote we store on deck. I've modified the oarlocks so it rows pretty well. Our 44' Steele came with a inflatable and a 8hp 2 stroke Yamaha. I put a 12' Porte Bote on that. The Porte Bote does not list max HP, it lists max engine weight. That said I NEVER have opened the thing up, even with two folks and gear.

I would look into finding a good used Porte Bote. They carry a LOT, are reasonable to row, are tough as nails and should plane nicely with 4 hp.

NOT. Lifeboat.

2¢

[alctel]

I have a 10' portabote that is apparently rated for 2HP or something (It's an old porta-bote model), I use a 6HP 2 stroke on the back and it seems fine

I don't often use the engine though, I prefer to row everywhere

Also if anyone wants to trade my 10' for an 8', I'd jump on that. The 10' is slightly too big to easily handle assembly on the foredeck

[Gemini Dreams]

I have lived with a WB8 for the last five years.

1. The motor makes them tail heavy! Stepping from the dock to just in front of the rear seat takes on water at the closest corner.
2. The rib kit is good but the PVC one is crap and will not hold air from my experience. It makes a good fender once you give up trying to keep air in it.
3. They sail well below 90 degrees.
4. They row fair but not as good as a plywood rowing dinghy.
5. The rear wheel is crap.
6. They are DAMN HEAVY for what you get.

Now onto the motor issue.

1. Most small outboards are Tohatsus but I have the Mercury version.
2. The 2.5 and 3.5 Mercury are the same except the carb. For the WB8 the 3.5 is only more money.
3. The Mercury 4 has a small pitch prop, the Mercury 5 gets a real prop, the Mercury 6 gets bigger jets and more rpm, They are all the same basic motor.
4. If in a bind you need to use a kicker off the main boat for the dinghy be careful installing over water as the transom end will swamp if you lean too far aft while doing this.
5. You should get a 2.5-3.5 for the dinghy other than the main kicker.
6. A 3.5 will push a cruise laden 27 foot boat at 4.2 knots in calm water.

In conclusion the ownership of a WB8 is a love hate relationship!


W

[hpeer]

Originally Posted by alctel

I have a 10' portabote that is apparently rated for 2HP or something (It's an old porta-bote model), I use a 6HP 2 stroke on the back and it seems fine

I don't often use the engine though, I prefer to row everywhere

Also if anyone wants to trade my 10' for an 8', I'd jump on that. The 10' is slightly too big to easily handle assembly on the foredeck

Have you tried assembling it vertically? Held up by a halyard? Huge difference.

[KISS]

Originally Posted by hpeer

KISS,
our 33' steel boat came with a nice little 7'6" dink designed to fit on th coach roof. The PO and dink builder was about 150 lb and his wife maybe 100lb. It worked for them. Not us, we had waaaay less freeboard than they did. Simply unsafe.

We now have a 10' Porte Bote we store on deck. I've modified the oarlocks so it rows pretty well. Our 44' Steele came with a inflatable and a 8hp 2 stroke Yamaha. I put a 12' Porte Bote on that. The Porte Bote does not list max HP, it lists max engine weight. That said I NEVER have opened the thing up, even with two folks and gear.

I would look into finding a good used Porte Bote. They carry a LOT, are reasonable to row, are tough as nails and should plane nicely with 4 hp.

NOT. Lifeboat.

2¢

Thanks

I've looked at the Porta Bote. In principle, it seems like a great solution.

But somehow I just can't fathom a boat that folds up...

Need to see one in person I guess.

[KISS]

Originally Posted by Gemini Dreams

I have lived with a WB8 for the last five years.

1. The motor makes them tail heavy! Stepping from the dock to just in front of the rear seat takes on water at the closest corner.
2. The rib kit is good but the PVC one is crap and will not hold air from my experience. It makes a good fender once you give up trying to keep air in it.
3. They sail well below 90 degrees.
4. They row fair but not as good as a plywood rowing dinghy.
5. The rear wheel is crap.
6. They are DAMN HEAVY for what you get.

Now onto the motor issue.

1. Most small outboards are Tohatsus but I have the Mercury version.
2. The 2.5 and 3.5 Mercury are the same except the carb. For the WB8 the 3.5 is only more money.
3. The Mercury 4 has a small pitch prop, the Mercury 5 gets a real prop, the Mercury 6 gets bigger jets and more rpm, They are all the same basic motor.
4. If in a bind you need to use a kicker off the main boat for the dinghy be careful installing over water as the transom end will swamp if you lean too far aft while doing this.
5. You should get a 2.5-3.5 for the dinghy other than the main kicker.
6. A 3.5 will push a cruise laden 27 foot boat at 4.2 knots in calm water.

In conclusion the ownership of a WB8 is a love hate relationship!

W

Thanks, the underlined is especially interesting!

That's much faster than I thought.

1 knot would have been acceptable.

[alctel]

Originally Posted by hpeer

Have you tried assembling it vertically? Held up by a halyard? Huge difference.

Whaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa


You may have just changed everything. Will give it a go tonight~

[Jim Cate]

I looked into the Pudgy: awesome piece of kit! ...But insanely $$$. I do plan to double the dink as a lifeboat (...subject for another thread). Not married to the WB 8, another make might be better. But it can't be much larger than 8, to fit where I need it (i.e. in a cockpit locker, on its side).

KISS, you may need to rethink your dinghy storage idea (in a cockpit locker on its side). Simply not practical, or even do-able in any ~30 foot boat I've ever seen... and not in many 50 foot boats... with an 8 foot hard dinghy.

Jim

[Martkimwat]

For some reason my first reply did not get through, so here goes again,I have a Walker Bay 8 that came from the factory with the inflatable tubes that are an accessory item ,already fitted, the manufactures rating plate says I can carry three people (as opposed to two without the tubes) and use a 4hp motor. My guess is that it is a stability issue to do with the power available whilst in a turn, as the tubes do not extend beyond the stern, and obviously the transom is the same, so it is not a strength issue. I use a Mariner 3.3 and have never needed to use full throttle, so I'm sure a 4hp at half throttle will be fine even on the Walker Bay 8 without the tubes.