Zodiac MkII vs. Bombard C3?

[headdamage]

The wooden keel is in three sections that lock together with the alum floor to make a rigid keel, the bottom of the boat is still soft though except for right along the center line of the keel. The wooden keel replaces the inflatable keel in a regular SIB.

Here is a photo of the keel on it's side:

[TheMadMariner]

Thank you for your fast and clear explanation, I have never seen a design like that, and find it rather interesting. I can imagine it's pretty difficult to assemble.

I've got a semi-rigid designed hull Sib myself, made by DSB.
It has an inflatable keel like most SIB's, but as an extra, consists of two rubber-coated boards that you lock to the transom and are positioned under the inflatable keel. Then you just roll back the keel and assemble the floorboards as in any other SIB. As you inflate the boat, the rubber-boards get pressed to the hypalon hull and by doing so reinforce the V-shape and make it the hull more rigid at this point.

I haven't got a picture to show you, but as soon as I take it apart for maintenance I'll upload some shots.

[headdamage]

Originally Posted by TheMadMariner

It has an inflatable keel like most SIB's, but as an extra, consists of two rubber-coated boards that you lock to the transom and are positioned under the inflatable keel. Then you just roll back the keel and assemble the floorboards as in any other SIB. As you inflate the boat, the rubber-boards get pressed to the hypalon hull and by doing so reinforce the V-shape and make it the hull more rigid at this point.

That sounds like a good system... I'd like to see photos of it when you get a chance

[headdamage]

Had a really good look at the MkII GT today. It is in good shape overall but the thrust board will need reattaching soon, not much of the keel tube is attached to the bottom anymore, and there are a few small warn spots that could use a patch. All items that can be fixed before next year.

Setting up the MkII is much easier than the C3. The intercommunicating valves are very nice to use compared to the three Boston valves on the C3, you only have to hook the pump up to one side or the other of the MkII and the whole boat is inflated to an even pressure. Each of the three valves on the C3 have to be pumped and it is a bit tricky to get the pressures even. Also the floor of the MkII is easy to install. The C3 flour is of the same basic design but the wooden keel makes it more difficult to set up.

I like the C3 but I'm used to the layout of the MkII because I've had a MkI for over 35 years and the wooden keel just might be too much of a pita for me, I'll be packing the boat down between uses and not putting it on a trailer.

Was going to put them on the water today but the wind has been blowing up to 60kph so that didn't seem like a good idea for a first time use of used boats and motor

[headdamage]

I couldn't find this on the web but I found a hard copy:

[captnjack]

Where are you located in Canada headdamage? The C3 is a good boat, I would sell it vs. canabalizing it for a DIY RIB. If you are close to Washington state maybe I can find you a buyer? Mine was a good dive boat.

[prairie tuber]

HD,

Do you have plans to trailer the boat? If so, you might want to look at the RNLI's solution to the loose thrust boards (search "bottle screw" in this forum). The other benefit of the inflatable keel over the wooden keel would be if you plan on using the boat on rivers with rapids.

[headdamage]

No I will mostly be packing the boat down for transport not using a trailer. I like the bottle screw type idea and had considered it for my old MkI at one time due to the wooden floor having some issues which I have since fixed.

For the MkII I really like the alum floor so I think I'll just have the thrust board fixed unless there is a good alternative to the trust board that still uses the original floor. Could I use something like the bottle screw between the alum floor and a new triangular bow section?

[bigscott]

Given the choice I would go for the C3. I had a mkII and the inflatable keel gave me endless headaches keeping it air tight. Am I right in saying the C3 has a deeper keel than the mkII? if so the ride should be a more comfortable

[headdamage]

Took the MkII out on the water today, it was great! Much nicer than the MkI in chop. Tried the 15hp Evinrude on it first for a test run, worked ok but a bit slow at 17kph WOT and it has trouble getting on plane when going with the waves.

Then I put the 30hp Johnson on and wow! The even with 500lbs in the boat it took of like a shot and would hold 34kph @ WOT. The 30hp is at the limit of what I would want to hand launch due to weight so I'm very happy it has enough power for the boat.

One thing I'm not sure about is the floor. When I got in some 2 to 3 foot waves the boat was bending quite a bit at the joint of the floor one panel back from the thrust board. The stringers hold the rear three panels together but there is nothing to hold this joint, am I missing a short stringer or something? See the below photo of the section.



15hp


30hp



The back of the motor cover says 25 but the motor is a 30hp.