History of dinghys and a deep think on why we like RIBs

[hpeer]

Think of a Porta Bote as a nesting dingy. It just nests the other way.

[Jammer]

Originally Posted by zeehag

i am sooo glad i got the need for speed out of my system before i went voyaging. there is no reason to need to speed thru an anchorage in a rib, or any other kind of small boat. yet this is THE occurrence of the day. gotta plane. dang

After some years of playing with motorcycles, airplanes, and cars -- all capable of speeds well into the triple digits -- roaring up the channel at 30 miles per hour in an inflatable boat seems to me to be very small beer indeed.


I get it about the value of crossing larger distances, but I'm having trouble imagining that I'd be comfortable going e.g. 20 miles down the shore with no way back if my outboard picks that particular moment to pack it in.

[KP44]

Originally Posted by Jammer

The central point I'm trying to make here, is that the alternative of a two-piece, nesting, hard dink that is sized to fit the larger cruising boats that now make up most of the fleet, hasn't been given serious attention by enough designers and builders. We have the PT-11, which is, by all reports, great for what it is, but is slightly too small and is only available as a kit.

You might find a port-a-bote will do what you need.

[Yellowjacket]

I've been doodling "my perfect dink" for a more than a year, for another hour this morning, and appreciate Jammer raising the topic. There's a lot of good thought on this thread. I wonder if there are enough "needs in common" for us to design "our best compromise:" Soft walls, easy storage, safe entry / exit, easy to power …

[Cheechako]

I think for most of us we have tried the other things. Also, I think there are two types of cruisers:
-One type travels far and wide in their dingy. 10+ miles sometimes, exploring where the mothership cant go.
-The other just wants to get ashore and can live with a little 8 ft hard rowboat.

I have had 8 ft hard dingies, inflatables, RIB's etc. Inflatables wont ding up the mothership. My little 8 foot hard dingy beat hell out of my boat in 2 years time. It was dangerous just getting to town in a decent wind chop. Often near swamping with 2 people aboard. We were limited to not going far.

[Pauls]

Regarding hard dinks, especially nesting ones, several years ago I did development work on a hull form intended to have very low drag at displacement speeds (ie rowing or sailing) as well as good performance at planning speeds. This was an interesting project.

What we eventually arrived at. after about 4 iterations, was a narrow double ender (the standard low drag displacement hull as in kayaks, canoes, racing shells) with a shallow arc bottom with absolutely straight buttock lines for the aft 70% of the hull length. Buttocks are lines showing the shape of the underwater part of the hull in the side view.

This hull has very low drag at displacement speeds. It also planes very well. It shows no tendency to angle the bow high up when planning. Instead the bow runs just above the surface.


It is an ideal nesting design because, being a double ender, each half can be almost the same length and still nest. The typical pointed bow, flat transom boat must keep the transom end much shorter to fit inside the bow section. This means that the assembled boat can be almost 2 times the length of the nested sections. I am building a 14' nesting tender for my boat to this design. The nested length is 7' 8".

[Jammer]

Originally Posted by Pauls

Regarding hard dinks, especially nesting ones, several years ago I did development work on a hull form intended to have very low drag at displacement speeds (ie rowing or sailing) as well as good performance at planning speeds. This was an interesting project.

What we eventually arrived at. after about 4 iterations, was a narrow double ender (the standard low drag displacement hull as in kayaks, canoes, racing shells) with a shallow arc bottom with absolutely straight buttock lines for the aft 70% of the hull length. Buttocks are lines showing the shape of the underwater part of the hull in the side view.

This hull has very low drag at displacement speeds. It also planes very well. It shows no tendency to angle the bow high up when planning. Instead the bow runs just above the surface.


It is an ideal nesting design because, being a double ender, each half can be almost the same length and still nest. The typical pointed bow, flat transom boat must keep the transom end much shorter to fit inside the bow section. This means that the assembled boat can be almost 2 times the length of the nested sections. I am building a 14' nesting tender for my boat to this design. The nested length is 7' 8".

I would be very interested to see what you have come up with.


One of my ideas this morning during the drive in was a boat with a small amount of tumblehome on the outside of the hull, and some foam in the hull such that the inside of the gunwales would be flat. Then a rub rail on the outside at the beamiest point. Three benefits, 1) a contact surface other than the gunwale for bumping up against the mother ship, 2) better ultimate stability, 3) emergency flotation without using up space in the ends that would be valuable for lockers.


Related idea was to mold in a projection running fore and aft inside to use for attachments of seats, but run it the whole length of the boat, and again fill with foam to get flotation without wasting usable space.



Another thought is to round the bow to a greater degree, somewhat like on a pram but less so and without a flat section, just a 6" radius, to shorten the overall length without affecting much of anything, and to provide a less pointy and more readily fendered surface for contact with the mother ship and whatever else.


With a double ender, how you would power it? Or is it oar and sail only?

[Sailorman Ed]

Jammer, stand anyplace on a rib and it is stable, not possible on most rigid dinghies. And I think much easier to get back into from the water. Others have cited the pros and cons. And for many of us, it is also the "life raft", not something I would want to rely on in a hard dingy. I'v taken our rib places I would never even consider in a hard dingy. A kayak fulfills the option to paddle in serenity. We have both.

[hpeer]

Originally Posted by Pauls

Regarding hard dinks, especially nesting ones, several years ago I did development work on a hull form intended to have very low drag at displacement speeds (ie rowing or sailing) as well as good performance at planning speeds. This was an interesting project.

What we eventually arrived at. after about 4 iterations, was a narrow double ender (the standard low drag displacement hull as in kayaks, canoes, racing shells) with a shallow arc bottom with absolutely straight buttock lines for the aft 70% of the hull length. Buttocks are lines showing the shape of the underwater part of the hull in the side view.

This hull has very low drag at displacement speeds. It also planes very well. It shows no tendency to angle the bow high up when planning. Instead the bow runs just above the surface.


It is an ideal nesting design because, being a double ender, each half can be almost the same length and still nest. The typical pointed bow, flat transom boat must keep the transom end much shorter to fit inside the bow section. This means that the assembled boat can be almost 2 times the length of the nested sections. I am building a 14' nesting tender for my boat to this design. The nested length is 7' 8".

Tease! Show us pics if not design. Please!

[hpeer]

Originally Posted by Jammer

I would be very interested to see what you have come up with.


One of my ideas this morning during the drive in was a boat with a small amount of tumblehome on the outside of the hull, and some foam in the hull such that the inside of the gunwales would be flat. Then a rub rail on the outside at the beamiest point. Three benefits, 1) a contact surface other than the gunwale for bumping up against the mother ship, 2) better ultimate stability, 3) emergency flotation without using up space in the ends that would be valuable for lockers.

This much of your descriptiom comes very close to a PB.

[hpeer]

WELL, I think I just saw the ULTIMATE DINGY.

Don’t know how long but it was a RIB

It had THREE 300HP Yamahas

And a bow thruster.

Four deck apes, all in uniform, white polo shirts with blue trousers, where musseling an exercise machine aboard to deliver to the mother ship.

I almost fell off the dock when he hit the bow thruster. Amazing.

[quandary]

The inflateables have only been reliably possible since hypalon etc allowed tough air tubes to be built. No doubt about the tradeoffs..ribs are virtually unsinkable, difficult to capsize, stable, less damaging to topsides when alongside, can be overloaded etc. BUT are very difficult to row..virtually impossible into wind and need bigger outboards than dinks. Depends on usage...in calm waters a dink is great. Offshore a rib feels safer.

[hpeer]

Quandary, (great name!)

That is the rub, a rib is safer as long as the motor works. Once you run out of gas you are almost completly at the mercy of others. I always carry a handheld VHF in the dunk, even though ours is a PB I modified to make it row easier.

We each have different nightmares.

[Dockhead]

Originally Posted by Jammer

. . . I get it about the value of crossing larger distances, but I'm having trouble imagining that I'd be comfortable going e.g. 20 miles down the shore with no way back if my outboard picks that particular moment to pack it in.

To each his own, I guess.


I no longer have this capability, but with my old dinghy, I DID go 20 miles down the shore, sometimes several miles out to sea, and, best of all, on all day cruises up estuaries I couldn't reach in the mother ship with her 7 1/2 foot draft.


Like any boat -- you either trust it, or you don't. The old Mariner 25hp was bulletproof, and I didn't mind going to sea with it.



I would love to have a boat big enough to have such a dink again -- it's really great having a capable dinghy, a proper little motorboat.


Just like some with superyachts like to have their helicopters -- I totally get that.

[captnGD]

If a 14 ft aluminum or fiberglass dingy gets swamped, you are done. If a RIB gets swamped you continue. My old Walker Bay 10ft RIB had cracks at the transom stringers and filled with water. You simply turned on the bilge pump and forward motion kept the water out. New 1018 Walker Bay 10ft RIB solved the problem with Walker Bay help.