Inflatable keel makes a bump in the air floor

[AndiD]

Hi all,

This is a 1999 Zodiac CFR340. Inflatable keel and air floor.
All is good, except for the upwards V shape in the middle of floor, right where the front wider part of the keel is. (This is not my boat - I found this pic online, but this is exactly what I'm talking about.
It's not bad, just a bit annoying that there's this raised bump in the middle of the boat when I fish standing up. Floor and keel are inflated to specs (11.2 psi floor and 3.6psi keel)
Could I add a side to side rigid wood slat under the floor in that area to prevent the keel from "bumping the floor" upwards?
Any idea would be much appreciated!

[Steve509926]

Hi AndiD,

This thread may help:-

https://www.rib.net/forum/f50/airdec...ign-87561.html

[Fenlander]

I've had two Zodiac 360s and two 340s with that floor design and yes they do tend to hump up a bit in the middle. It is a "feature" of a flat air floor hence other makers fitting a stiffening board as in Steve's linked thread.

We never bothered with the Zodiacs and accepted it.

[AndiD]

Originally Posted by Steve509926

Hi AndiD,

This thread may help:-

https://www.rib.net/forum/f50/airdec...ign-87561.html

Wow, that is perfect!! Thank you!

[AndiD]

Originally Posted by Fenlander

I've had two Zodiac 360s and two 340s with that floor design and yes they do tend to hump up a bit in the middle. It is a "feature" of a flat air floor hence other makers fitting a stiffening board as in Steve's linked thread.

We never bothered with the Zodiacs and accepted it.

Thank you for the reply! Yes, I am working towards accepting it, but I will definitely play with the project in the previous post. am torn between adding another step to the boat setup and simplicity (simplicity with a hump )

[AndiD]

Now, what happens if I don't inflate the keel at all or only partially? I only use a 65lb thrust trolling motor and will be using this Zodiac on mountain lakes (buying a different one for saltwater in FL).

[Steve509926]

Never tried it, however I think you would have a lot of drag on the sib through the water due to the pvc not being forced taut by the inflated keel, a bit like dragging a sea anchor.

[AndiD]

Originally Posted by Steve509926

Never tried it, however I think you would have a lot of drag on the sib through the water due to the pvc not being forced taut by the inflated keel, a bit like dragging a sea anchor.

That makes sense. The keel tightens the floor.
So I have 3 options:
1. Live with it and adapt
2. Install the support that you kindly demonstrated
3. replace air floor with plywood floor.

I guess it will be up to how I feel on the boat this summer...

[User name]

One of mine comes with a plywood plank like you describe that spans the floor just rearwards of the valve and it prevents this bow from happening. You could make one up pretty easily. If you wanted to get creative, you could also make some fabric loops to attach it to the air floor itself. That way you won't have to worry about the risk of it shifting around underneath.

[Steve509926]

Originally Posted by AndiD

That makes sense. The keel tightens the floor.
So I have 3 options:
1. Live with it and adapt
2. Install the support that you kindly demonstrated
3. replace air floor with plywood floor.

I guess it will be up to how I feel on the boat this summer...

3. has been talked about before on the forum but I don't know if anyone has done it. Personally I think it would be more hassle than it's worth.

[AndiD]

Originally Posted by Steve509926

3. has been talked about before on the forum but I don't know if anyone has done it. Personally I think it would be more hassle than it's worth.

Maybe I'll be the pioneer

[willk]

Originally Posted by AndiD

Maybe I'll be the pioneer

You could be!

I've had an inflatable with this system and it's very important to get everything up to pressure and tight for high speed use - not so much for an electric pusher motor. If the airdeck is hard enough to stand on and the keel pulls the hull skin downwards into shape, IMHO, you'll be fine.

[AndiD]

Originally Posted by willk

You could be!

I've had an inflatable with this system and it's very important to get everything up to pressure and tight for high speed use - not so much for an electric pusher motor. If the airdeck is hard enough to stand on and the keel pulls the hull skin downwards into shape, IMHO, you'll be fine.

Like you said, at 4.5 mph max I won't see a difference. I am just looking for comfort and stability when I stand up...