Water in the skirt

[raytoews]

My surveyor has always had a problem with water staying in the skirt.
I cut the hole in the rear skirt as per the plans but any time I set down in the water the skirt fills with water and wont drain.
If I can find a sandbar and ride up onto it that does it but it is so sluggish it is hard to get up onto any slope.
It feels like the corners are filling up and the water can't get up to the middle to drain.
I cut two holes in the corners about 2 inches and left the flap but no success.
I am thinking of gluing all the flaps shut and burning a few holes on the very bottom of the rear skirt???
I'm stumped.

Ray Toews
Fort Vermilion AB

[beezer]

I'd start with a close check of the skirt itself. check the position of the drain. if not that, put the craft on blocks so the bottom is 10.5" off the floor & see how the shirt inflates (disconnect the thrust prop). look in the back where the fill strips are & see if there is evidence of it being bunched up or twisted. if the skirt is puckered it may be trapping water. Or, block the hull up to about 33-34" (the skirt ground contact line is 33.6 I think) & pull the skirt down even all around until it almost touches the floor. this is how I've been sizing the "fill" strip.... by pulling the skirt down to the contact line all around the hull. the first skirt I made was short in the fill & one cheek (more than the other) would drag slightly. it was noticeable from the back when following & had a bit more spray as well.

[AJW]

I also had problems with rear skirt fitment on my surveyor. I cant emphasise enough the importance of blocking the hull to the correct height when trimming / checking the skirt. My rear skirt was banana shaped because I had messed up with the fill strips.

On my last skirt I was able to use the ground contact lines that were marked on the skirt to check against lines drawn on the floor to ensure the skirt was fitted properly.

If the skirt is not draining then there is a problem with the skirt

[bphillip2]

How do you know there is water in the skirt? What is the symptom or evidence of this? How much flotation do you have?

[jchovernut]

Do you have the rows of flotation on either side of the GCL? Does it actually float? It should lay nearly flat on the water when floating off cushion. Some foams retain water & don't float so well after a while. Bryan sells some top-notch foam that works great!! There's a LOT of volume in a SEV skirt, & it it's not floating properly, you can sit there & purge forever!!

[beezer]

I've been thinking about this... "feels like the corners are filling up and the water can't get up to the middle to drain"

that sounds like you are talking about the aft part of the skirt.... the "middle" of the back tube being where the drain is. if so, I would say either the fill strips are too long or the part that attaches to the splitter bar is too short. the easy fix would be to add to the piece on the splitter & see if that helps. if you block it up & pull the skirt down I'll bet you see a rise at the drain. if the fill strips were installed with the skirt attached to the splitter bar, they may be misshapen too

[AJW]

If the blocks are fixed to the bottom of the craft "well basically how it is shown in the videos to trim the skirt" If the skirt shape is wrong you will be able to see it while engine is running at enough rpm to inflate the skirt. I was able to get my arm through the gap between the floor & the centre of the rear bag as the gap was that big

Be careful just adding material to where the skirt meets the splitter bar, I done that and ended up with too much material on the rear bag, which then scooped the water I couldn't figure out what was happening until John Robertson came out on the craft with me and he spotted it through the lift duct. I blocked the craft up at 10.5" used a large set square to mark the outside of the craft on the floor with chalk, then used this line to make sure the ground contact lines on the skirt lined up with these lines. I had to remove the extra material I had put in the lift duct to skirt flap and remake the two infill panels.

We are assuming it is a skirt problem you have. Have you weighed the craft & checked that the CG is correct? Just wondering if the craft could be too heavy or rear heavy.

[bphillip2]

We are not getting any feedback, but it sounds more like a craft without skirt flotation and that won't plane.