RIB sizing for family of 4 plus med/large dog?

[Whitebread117]

Greetings all,

First, if this is in the wrong subforum, mods please move it to where it belongs. But since this is a question specifically for those out there with kids (and pets) this was my best guess for location.

I've been lurking on this forum for about a year now planning our change in lattitude. One question I've not seen answered (and probably I'm just not searching for the right keywords) is: What size RIB/motor would be preferable for a family of 4 plus a 55lb dog?

Background info:
Husband/wife early 30s, I'm 6'3 she's 5'6
2 kids aged 8 and 5, tall for their age
We're not fitness models but we're not couch potatoes, no weight or mobility issues.

The environment: We're starting out poking around the Bahamas, then headed south and eventually way west as the kids get a bit older.

Need a RIB for frequent use exploring and ferrying family (plus supplies or dog- not likely both at once) to/from boat anchored out. Boat is yet to be finalized, but will likely be in the age/range of Pearson 365 to Allied Mistress, meaning 36-40' but not particularly beamy by modern standards. RIB needs to fit on davits for day to day, but fit on foredeck for passages.

I don't want any excess bells and whistles, but I want a tough dingy and would rather pay a bit more once than go cheap and settle for aggravation over time. That being said I'm assuming I'm looking at AL floor and Hypalon tubes. $5-7k is the reasonable max budget for RIB plus motor. Less $ is better but if there's a bump in quality that's usually worth it. Planing ability preferable but not absolutely required.

Biggest question is what size am I looking at? Going just by weight capacities it looks like 10' or so but looking for advice from those with first hand experience. Thinking motor would need to be at least 15hp to have any chance of planing but don't want to go over 20hp or I'll be the only one who can load/unload the thing. 2 stroke vs 4 stroke I don't really care, with a very slight bias towards 4 stroke.

Second question is what brands of dinghy/motor combo would you recommend? I know most of the big brands for both but still would like to hear positive and negative comments on specifics. Time frame for checking out is 12-18 months, so only looking at current production models.

Thanks in advance for your help, this site has proved to be an excellent resource thus far.

[Cheechako]

a 10 will be pretty marginal for that crowd. Unfortunately that leaves you at probably a 12 footer! Two of us in a 10 ft Caribe felt cramped with a chop and bags of groceries. You're going to need some HP too unless you don't want to plane... I'm guessing at least 20 hp...

[svTOTEM]

With 3 kids, our 3.1 meter with 15hp fit us very well. When this excellent 1994 Avon dinghy (fiberglass bottom) finally failed last year in Thailand, we settled for a 2.9 meter replacement (aluminum bottom), since no 3.1 was available. We like the lighter weight of the new one, but 3.1 meter was a much better size - handled big loads for swimming excursions and carring gerry cans of diesel much better. It handled sloppy seas better, which was party due to more weight. Everything is a compromise. Good luck!

[Whitebread117]

Originally Posted by Cheechako

a 10 will be pretty marginal for that crowd. Unfortunately that leaves you at probably a 12 footer! Two of us in a 10 ft Caribe felt cramped with a chop and bags of groceries. You're going to need some HP too unless you don't want to plane... I'm guessing at least 20 hp...

That's what I was afraid of - 10' minimum for weight, but bigger if you want any room. Planing fully loaded is not too big of a concern, but enough power to plane off with 2 of us (or 4 if I teach the kids to hike on the bow ) would be nice.

Thanks for comment

[Dhillen]

I agree with your assumptions. We tend to look at the dinghy as the family car. It needs to be big enough to carry everybody with groceries and laundry. Don't forget, that 55 lb dog is probably 70 lbs wet. From a safety point of view, especially with children aboard, it also needs to be reliable. Don't skimp on the dink.

Since you don't have a boat yet there is no rush to get a dinghy as the boat you eventually buy may have a great dink. If it doesn't then sell the old dink and get a better one.

For longer term cruising in the tropics you are correct in wanting Hypalon (don't get anything else or you will regret it) and either a GRP or AL bottom. GRP will do the job but it is heavy. Think about getting that dinghy on deck every night by yourself. (Since you are going to the Caribbean that dinghy needs to be aboard EVERY night if you want it there in the morning).

Ten feet is a good size for a family of four. Eleven is better but again, think of weight and how you will be maneuvering that sucker on and off the boat every day. Go for the 15 HP outboard. Yamaha is perceived as the best. I have a Tohatsu and have been very pleased with it but then again, I also had good luck with my Yamaha (until I dumped it in the bottom of the harbor in Sri Lanka - and then it got stolen in Sudan, but that is another story).

If you can get the older 15 HP two-strokes they are much, much lighter than the newer gen four-stroke models. I believe you can still buy these in the Caribbean and some cruisers on the east coast, USA still have them. Again, be thinking weight and about you hoisting it up alone in bad weather. I have a four-stroke jobber and it is fantastic: quiet, sips gas but it weighs half a ton. Thankfully, my davits take care of that.

Good luck.

Dhillen

[Wind River]

I can't speak for what you need but this is what I have and what it will and will not do.
I have a 2009 West Marine RIB350 (11.5 ft.) with a 25hp Mercury 4 stroke outboard (also 2009). It carries two adults, a 70 lb. dog and misc gear and groceries and will plane and move along fine, probably faster than I really should be going. Put four adults in it and no matter where you put them in the boat, it will not get up on a plane. That was very disappointing to me as I was hoping to get 3 adults and dive gear up on a plane to get out to the dive site in a hurry.
I have not tried changing props or anything else to improve the situation but my guess is that is why I found this virtually new dinghy and trailer for sale. I was told the previous owner was 350 lbs+. Probably didn't move him as well as he hoped either.

[MarkJ]

I have a 9 foot dink and 18 hp 2 stroke which is fine for one...

You would like a bit bigger dink.

BTW its not going to fit on your foredeck.. And if it did how do you get to the forestay, anchor etc.

Much better on davits at sea. Get good davits and lash it down.

[SV Lift]

That's the formula for dinghy happiness.

-10' RIB with 15hp
-Hypalon
-Aluminum if you have lots of cash, GRP if not
-AB/Caribe/West Marine in that order depending on said cash
-Yamaha or Tohatsu - 2stroke if truly sailing around the world / 4stroke for US/Bahamas/Caribbean
-DAVITS

[JK n Smitty]

We went with the Highfields 9'6" AL Rib with the double floor. Very happy with the boat. It's typically just the 2 of us and we (well really just me) are larger. With us and the dog the weight is probably 550 lbs. We have had 4 adults plus the dog in the dingy no problem. We only live on a 31 footer so we went with a smaller dingy.

Keep the weight of the motor in mind. The engines you are talking about weigh 90-125 pounds. That's a lot of weight to lift and on the rail. We use a 2-stroke 9.8 hp that weighs 57 lbs. I wouldn't want to deal with a heavy engine for the dink.


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[Vasco]

A 10'06" AB RIB will do with a 15hp Yamaha 2 stroke. Enough to plane with your family including the dog. I think the figlass one will be better than the aluminum one as it has a flat floor.

[Whitebread117]

Thanks for all the replies so far. It's very helpful to hear opinions from end users instead of just mfr's sales-oriented recommendations.

[accomplice]

In 3.8m Gemini RIB, with 15HP Honda, we carry 4 adults plus bags no problem -- we do 5 people plus dog often. Getting on to a plane is easy with 2 or 3 aboard, hard/impossible with 4 or 5. I find that most of my dinghy usage is not on-plane anyways because in a harbor I don't want to disturb others.

[JPA Cate]

This one is going to come down to how big a RIB you can actually stow disinflated on your foredeck. Make any possible deals contingent upon it's fitting there. (Dealers usually do not know this dimension, so trial fit is the way to go.

I'd recommend a 3.4 m. dinghy, if it will fit. With a 15 hp 2 stroke, and possibly a special prop (keep the one that comes with the motor for a spare.

Cheers,

Ann

[Whitebread117]

Originally Posted by Ann T. Cate

This one is going to come down to how big a RIB you can actually stow disinflated on your foredeck. Make any possible deals contingent upon it's fitting there. (Dealers usually do not know this dimension, so trial fit is the way to go.

I'd recommend a 3.4 m. dinghy, if it will fit. With a 15 hp 2 stroke, and possibly a special prop (keep the one that comes with the motor for a spare.

Cheers,

Ann

Thanks for the response, that's a very important point.

I've spent most of my life in the industrial automation/electrical/maintenance fields. A very important part of those fields are evaluating design criteria vs actual field conditions. I'm all for the biggest dinghy I can afford on davits out back up high and lashed down (where it's convenient to deploy and retrieve), but also I'm fully aware of what forces would be asserted on the davit mounting points and (if the mounting points hold) the transom by a suddenly swamped dinghy cantilevered out on davits.

There's a few flush decks in our short list of potential boats so that might change available space a bit. Either way I'm going to be looking for a way to get the dinghy off the davits and onto the deck for anything more than a short hop, even if it means a custom rack (I'm a welder too so that's not cost prohibitive). Several folks have mentioned foredeck space issues so I'll be sure to measure carefully when getting serious about buying. I'm not planning to buy any dinghy until we take possession of the mothership, however most of the boats we've looked at come with either davits and no dinghy or a dink that fits 2-3 at most. So best to decide what's needed ahead of time, because the chance of lucking into a boat with the ideal dink included is not likely in our price range.

I'm thinking planing fully loaded is on the very limit or out of the question for the boat/dinghy/outboard sizes I'm considering, but that's no problem. If we know we can physically fit everyone/thing safely without extreme discomfort on a 10-11' RIB when running a mile or so to/from town at displacement speeds that's the important thing. Ability to plane for longer distances when lightly loaded while using a motor that most adults can load/unload (with block/tackle if needed) is an added bonus.

Regarding the prop choice, am I right in assuming you'd recommend a steeper(lower) pitch for more thrust when loaded?

Again thanks to all that have responded. I have a lot of experience with wood/aluminum skiffs in the 10-14' range, but the carrying capacities/hp ratings are completely different than inflatables so all of this info is very helpful.

[malbert73]

I prefer a inflatable floor/roll-up for our current part time cruising, mostly chesapeake bay. Once we start venturing further and longer, a RIB completely makes sense.

Is there a downside to the aluminum hull RIBs? I would imagine lighter is better- can plane with smaller outboard, etc. Or am I missing something?