Hard or Soft Dinghy For A 34' Sailboat?

[Joe Mullee]

My thirteen year old West Marine rollup inflatable (8'6") developed a slow water leak this season along one if its' floor-to-tube seems. That slow leak turned into a gusher yesterday. I'll try to fix it this weekend but it got me wondering again if a hard dinghy would be a better fit for my uses.

Just curious if your boat is similiar in size to my Hunter 34 what type of dinghy you use, what you like about it, what you don't like, and how you transport it while on the water.

I use my dinghy two to three times per month. It's fairly easy to blow up on my foredeck and generally I have no problem hoisting it and retrieving it over the lifelines (I think it weighs about 70 lbs). When moving between achorages I tie it down just forward of my mast on the foredeck. In ten years of ownership it I think I've only towed it behind a half dozen times. When I'm back in the slip it gets rolled up and placed into it's storage bag where it stays on deck just forward of the traveler or down below in the aft cabin. Pretty simple set up.

What I don't like about it is it doesn't row well and when I use the 3.3 hp engine it doesn't plane. Since I don't have any davits on my boat it's also an acrobatic feat lowering the outboard from the stern pulpit to the transom on the dinghy. So I'm just wondering what others use and how they like it.

Thanks,
Joe Mullee

 

[kloudie1]

I have an inflatable but I'll bet it has less than 20 hours of service on it since I bought it new back in '91..it stays rolled up in the aft cabin.. If I were to do it again, I would probably go with a Porta-Bote .. Store it on lifelines inside a canvas sleeve during sailing.. or tow behind with engine removed on short hops.

EDIT: A note on the tests..
http://www.porta-bote.com/practical.php

 

[Steve Kamp]

We use a hard bottom hypalon 11" 6" with the davits mounted on the arch of our 2005 Hunter 38. (Prior to that we had a 10" 6" Walker Bay, and rowed everytime we went ashore.) We use a 6 HP merc, and get around most anchorages very well with a load of two adults plus groceries. We launch the dink first, then lower the merc from the stern rail mount with one of the davit blocks.
In your situation you could consider a block rigged to the end of the boom and swing it outboard with the motor after you launch your dink. For that matter you could also launch your dink from the deck or cabin top using the boom and a block, or from the foredeck using a halyard.

 

[Allan12210]

Joe,

We have a Seaworthy that we purchased from Boat US around the same time Claude (Kloudie 1) did. Very similar usage as well. It is 8'2" and I like it as I put it on the foredeck about 2 " back from the anchor locker door so that works. The transom is just forward enough that I can unclip my whisker pole that is stowed vertically up the front of the mast and swing it out and around the tubes. We usually only have it inflated during the summer (and used for a week long cruise to Monterey in July and again for the Labor Day weekend to Half Moon Bay). The rest of the time its deflated, rolled up and stored in the aft lazarette with the wooden floorboards. That's why we really like our boat...lots of storage in the back lockers for some really big stuff. The outboard lives at home.

Allan

 

[Stu Jackson]

Joe, you really can't have the best of both worlds.

What I don't like about it is it doesn't row well and when I use the 3.3 hp engine it doesn't plane.

Larger engine & boat = ability to plane.

Smaller engine = slower, regardless of type of boat.

No davits? Do what you've done or tow.

Engine, regardless of size unless it's 1.2 HP egg beater = Garhauer dinghy motor lift. (Great product).

Have you tried the "inside" dinghy sealant yet or is it too far gone?

 

[Joe Mullee]

Decision made. I'm going to try to fix what I have and if it's too far gone look for another rollup inflatable. After reading these posts, looking thru the archives, and speaking to some others the inflatable is the way to go for me. I prefer not to tow, need the platform to be as stable as possible, like to be able to store it away, and planning isn't an absolute requirement. I will look into a Garhauer motor lift too.

Thanks Claude, Steve, Allan, & Stu.

 

[kloudie1]

Ya welcome, Joe.. A water leak should be fixable since it is not holding air pressure.. ya might be able to stitch the patch to the tabs still there (not into the air chmber) and seal with glue if all else fails..
Good luck with it !

 

[Claude L.-Auger]

Hi Joe,

Once you fix the leak, I have found a way to hoist the dinghy behind the boat. Suspend it from the top of the mast !!! When you're done laughing, consider this: I ran a halyard in the mast using the spare sheeve next to the main halyard sheeve, (both on top and on the bottom of the mast). I made a sling with safety belt material and attached 4 hooks to the 4 arms of the sling. 2 hooks are attached to the dinghy transom (I installed eyelets) and 2 hooks are attached to the D-rings each side of the dinghy bow. For better support I also have a piece of sling going from side to side under the bow so it is not supported just by the D-rings.

I have brought the halyard to the cockpit and use the winch on top of the cabin to hoist the dinghy. Once where I want it, at the same height as the top of the stern railing, I secure the dinghy bow and stern to the railing.

Take a look at the attached pics. I also have a few videos (filmed on the lower St.Lawrence river, under 42 knots, no main just about 40 sq. feet of jib), but can't seem to upload them.

Safe under all conditions, I have had that system for 6 years now and have not had a problem ! And... I'm now smart enough to leave the dinghy drain plug undone when hoisted so that it does not get filled-up with rain water.

 

[robertsapp]

Wow. That just seems like a really bad idea. It goes without saying that your rig wasn't designed for a load like that. Oh well, your boat, your rules. Good luck and stay safe.

 

[Claude L.-Auger]

Wow. That just seems like a really bad idea. It goes without saying that your rig wasn't designed for a load like that. Oh well, your boat, your rules. Good luck and stay safe.

Robert, the soft bottom 10' dinghy weighs less than 100 pounds including the plywood floor-boards. What do you think the load on the rig is when sailing in 20 knots of wind ? Far greater for sure !!! As mentioned 6 years since installed, but 10,000 miles in those 6 years, with trips to Labrador, Magdalen Islands, and the Bahamas under all kinds of conditions. Not one problem ! I never have done it, but feel I could probably leave the OB on it as I have tested it by getting into it while at the dock. So far, the only real drawback is the same as davits. I have to lower it out of the way if I want to use the swim ladder. I can swing it to the side of the boat, but it gets tricky because of the bimini. Good luck with the up-coming hurricane

 

[robertsapp]

Robert, the soft bottom 10' dinghy weighs less than 100 pounds including the plywood floor-boards. What do you think the load on the rig is when sailing in 20 knots of wind ? Far greater for sure !!!

Yes, and that far greater load is distributed fairly evenly over the entire length of the mast and boom, while what you have done is add a concentrated point load at your rig's weakest spot, particularly if you have a fractional rig and the forestay does not offset the pull from the dinghy. I'm no naval architect, just a plain old engineer, but I have this uneasy feeling that what you're doing isn't a very good idea. Just because you've gotten away with something for a while doesn't mean it's safe. Anyway, like I said, I'm no naval architect. Maybe there's enough excess margin built into the spar cross section to handle a load like that. Maybe there isn't. I don't know. I doubt you do either. I am fairly certain that it's something the original designer of the rig never considered or planned for. And that makes you just plain lucky in my book. But as I said, your boat, your rules. I'm not saying your wrong, I'm just saying it's something I'd never ever even consider doing, much less recommend to someone else. Maybe eventually someone with more rigging or design experience may weigh in with an opinion. Now I need to go get ready for a hurricane...

 

[PilotAlso]

WOW, a lot of people have been risking death and destruction when using a bosun's chair attached to a halyard. Concentrating their body weight (I'm at 230) on the "rigs' weakest point" is surely asking for trouble.

Robert, I must ask if you've ever heard of heeling a boat using large water bags? The bags weigh much much more than a 100lb dingy and are also attached to a spare halyard.

sample video: http://www.youtube.com/watch?v=epz6BBZm__0&feature=player_embedded

Claude, if you haven't noticed, I like the idea and plan to give it a try on my boat. I've never been one to worry about the sky falling.

Al

 

[waternwaves]

I might be able to shed a little light on this........

The in mast sheave is arguably the "weakest point" As the compression strength of the mast is enough to counteract the tension in numerous shrouds and stays.

Be it as it may, the lowest working rating I see in the harken catalog for that size and location would easily convince me that the working load for the masthead sheave/pin system has the capability to support the dinghy bouncing around,

and without going into trig/vector analysis.... and looking at the size of the pins and rivets and welds in my mast. .....
The 5000 lb working load lead fixed block rating on the end of a 60 ft dacron, vectran, dyneema line is easily within the capabilities of the mast.

I wouldnt hang a motor from a single line suspended dinghy, but the weight load is almost insignificant to the rigging loads. I would suspect the weak link would be the clutch block holding the line, or the riveted cleat the line is tied off to.

The mast is not going to deflect significantly nor should you worry if properly tensioned, nor the halyard, nor the sheave, nor the webbing for the dinghy.

and yes I am a trained Engineer. The dynamic loading a rigid dinghy would apply to a single line in tension is within the working loads of the components. IF you have a 7/16- 1/2 " halyard you are fine. Dont use a steel cable.

 

[Claude L.-Auger]

Since I originated this discussion about suspending the dinghy from the mast I'll go on record as saying to Robert that I never recommended it: I simply said that's what I did and explained how I did it. And I also said I did not leave the OB on the dinghy.

That being said, I worked for 10 years in the polyester and cordstrapping industry and became very familiar with dynamic load forces in many types of environment including impact testing at the Association of American Railroad (AAR) testing center in Pueblo Colorado.

Waternwaves, for your info, the pins on the mast sheaves are 3/8", the line is 7/16", going through a back-plated deck organizer with 2" sheave and through an Easylock line stopper which is through-bolted. I really feel the Wichard shackle at the end of the line is probably the weakest point and I'm not worried about it. The suspended dinghy doesn't bounce around since it is also secured front and back to the stern railing.

Thanks all for your comments and good luck to those of you in the path of Isaac.

 

[Mark48]

This thread really got off track, while the originator made a decision I am still curious as to thought on a hard or soft dinghy and length.

 

[Dan Johnson]

Claude A...

Loved your pix and your solution. Very simple way to boat a dinghy...

 

[robertsapp]

WOW, a lot of people have been risking death and destruction when using a bosun's chair attached to a halyard. Concentrating their body weight (I'm at 230) on the "rigs' weakest point" is surely asking for trouble.

Robert, I must ask if you've ever heard of heeling a boat using large water bags? The bags weigh much much more than a 100lb dingy and are also attached to a spare halyard.

sample video: http://www.youtube.com/watch?v=epz6BBZm__0&feature=player_embedded

Claude, if you haven't noticed, I like the idea and plan to give it a try on my boat. I've never been one to worry about the sky falling.

Al

Thanks for setting me straight on my ridiculous concerns, your snark really added much to the discussion. Wait a minute, it just occured to me - when you go aloft in a bosun's chair, your weight is applied in column. And those water bags - I'll bet you apply those loads laterally, in the same plane as all those shiny wire thingies that hold up the sides of the mast. But I'm sure you're absolutely right. Pulling backward on the top of a thin aluminum tube at a point eight to ten feet above where the forestay connects is probably exactly the same thing, right? I mean, what could possibly go wrong.

See, I can do it to. Now we can talk about the differential integration of the vector analysis of the designed load rating blah blah blah, but let me ask a more basic question to put it in perspective. How hard can you pull backward on the top of an unsupported, thin walled aluminum tube before it yields? That's all I'm saying. My gut tells me if it's a masthead rig, it's probably fine, but if it's a fractional rig, the margin to failure is probably closer than you think. That's my view of the matter.

Sorry for the delay in responding, but we took advantage of the decent weather to take the boat out of bondage after Issac and spend the long weekend gunkholing.