inflatable advice

bazley8 · 23 June 2011, 06:35

i currently have a 6 year old waveline 2.9m inflatable with an air mattress floor which can take up to an 8hp outboard,i have recently bought myself a 9.9hp mercury and when i go over half power the dinghy floor moves around alarmingly .my question is if i bought myself a 3.2m waveline again with the air mattrees floor but with a max engine capacity of 15hp would this solve my problems many thanks in advance

jake 4589 · 23 June 2011, 08:11

Hi there and welcome,

First question is are you sure the floor is up to the correct pressure?

Secondly, If you have insurance then using the 9.9hp Mercury on a boat that has a max engine rating of 8hp will probably render your insurance invalid.

Best wishes

Jake

Fenlander · 23 June 2011, 08:25

I'm a recent convert to air floors and have read about them intensively for the past couple of months and what folks see as their issues.

I'd echo what Jake says... Do you have a gauge to know you are getting up to pressure? Are you sure that gauge is accurate? Are you sure you have the correct pressure for your boat (is it on a tag near the valve or similar so you're sure).

If you are over-sensitive to them the natural movement in properly inflated air floors seems to put some folks off... they will never be truly rigid.

Next thought if you think of an upgrade might another make have a less flexy air floor?

willk · 23 June 2011, 10:11

The problem is the pressure in your inflatable keel and airdeck. It's not an air "mattress" - it should be as hard as a board! You will need a pressure gauge to do this correctly. In the case of my tender, the tubes are 3.6psi but the deck is 11psi - big difference.

The 9.9hp should be ok if the weight doesn't exceed the transom limit. You might want to consider a little extra sheet of ply on the transom to spread the thrust from the engine. My 2.7 seems to use that idea to boost it's rating up to 10hp. I can show you a pic if you want.

As regards insurance, if you don't have any then no issues! If you do, you should clear the engine with the company - I understand that generally they are cool with it on wee beach toys like ours.

Expect a very fast little boat when you are sorted - I'm getting 20mph from mine.

bazley8 · 23 June 2011, 15:57

update, bought about 2 foot of plywood laid it in the bottom of the boat below the air deck next to the transom made a world of difference

willk · 24 June 2011, 18:34

Quote:

Originally Posted by bazley8

update, bought about 2 foot of plywood laid it in the bottom of the boat below the air deck next to the transom made a world of difference

In case I'm responsible - that's not what I meant. I meant on the outside of the transom, vertically. Have you checked the air pressure in your floor? If it's not correct, I'd suggest that the ply insert is doing something unnecessary that may cause damage eventually...

bazley8 · 24 June 2011, 19:27

Quote:

Originally Posted by willk

In case I'm responsible - that's not what I meant. I meant on the outside of the transom, vertically. Have you checked the air pressure in your floor? If it's not correct, I'd suggest that the ply insert is doing something unnecessary that may cause damage eventually...

dont worry i know thats not what you meant,how can you tell the pressure in the floor is it just a case of buying an air pressure gauge thanks for the reply.could you show me a picture of exactly what you have done with your transom and the plywood many thanks

willk · 24 June 2011, 19:42

Max has made a cracker here.

You can buy them too, for a (big) price.

Quicksilver sell a pump with the gauge and various fittings.

If the pressure isn't right - the boat won't work properly - the air pressure is needed to provide the "spine" of the boat. I did 24 miles today in mine in bumpy enough seas and it didn't flex at all. I had taken special care with the floor and the keel. Sore on the arse though...

bazley8 · 24 June 2011, 19:50

thanks i would really like to see a picture of the transom with the ply

willk · 24 June 2011, 20:01

Quote:

Originally Posted by bazley8

thanks i would really like to see a picture of the transom with the ply

I'll take one for you tomorrow. It's not a mod, Quicksilver make them like that. Basically it's a spreader plate about 18" by 10" made of 1/2" ply bonded to the outside of the transom where the outboard is fitted. It's a bit odd and I've not seen one on another SIB. I think it's how QS have rated their boat higher than others in the size.

Not that an extra 2HP is a big issue

bazley8 · 24 June 2011, 20:03

ok thankyou

willk · 25 June 2011, 19:06

In retrospect, I wonder is it's purpose to protect the vinyl covered transom? I dunno!

bazley8 · 25 June 2011, 19:09

thankyou very much

bazley8 · 12 July 2011, 14:36

update, bought myself a plastimo 2.7m rib amazing difference