Main Surfski Modifications Page

Tom Halsted Aug 26, 2021 #29954

Anyone else with a Vega Flex have issues with it not draining much - even at 8mph? It means I'm carrying a lot of sloshing water and weight around while paddling.

I finally modified my drain venturi outlet by wedging a curved piece of an old cash card into its outlet. Doing so extended the lip of the outlet and probably helped to break up laminar flow. Now it fully drains at about 6.7mph. It even buzzes nicely whist doing so.

I played boat proctologist with a few other Flex's after a WNR, and could tell that the openings were slightly different on several of them.

Not yet sure what the perfect aperture, angle, diameter, or shape SHOULD be, but I know that some folks' Flex's drain just fine, just as they were shipped.

Thoughts?
Ideas?
Other than to stop using the term “proctologist”…

beau whitehead Aug 26 #29956
Tom, have you tried contacting Kai directly?

kaiwaacanoes@gmail.com

Michael Lee Aug 26 #29960

Hi Tom,

Please let us know if you get any feedback from Kai regarding the drain. The Vega has received many rave reviews, but there seems to be room for improvement in drain performance.

Michael J. Lee

Paul Reavley Aug 26 #29961
There have been a number of comments on surfski.info about the drainage:

surfski.info Flex/Vega drains and mods

Reivers Dustin Aug 26 #29962
woah. excellent discussion on surfski.info … great link Paul.

I have an inch of water in the footwell at all speeds. Except I can't look in there at high speeds - that would be multi-tasking.

Drainage is the one design fail in an otherwise gamechanger design. I'm convinced that there were copyright/patent obstacles for the builder putting any of the proven designs in there. I'll study the workarounds a bit before carving up my very expensive boat.

Because the flex has a different 'feel', people think it is less stable. Hopefully this misunderstanding will last a while longer. As Oscar said many years ago, “lighter is better.”

rd

James Schulz Aug 26 #29963

Tom,

Here’s a two minute video with a 60 second surf at the end surfing some mosquito farts.

https://www.youtube.com/watch?v=SfttlsXFITA

There is a phillips head screw right behind the venturi on the bottom of the boat that somehow holds the guide rails for the original Vega drain system. I used JD’s demo boat in the Gorge recently and he had removed that screw and guide rails. It might not make the venturi more efficient but it may help it gravity drain the water level inside the cockpit to the water level outside the boat a bit quicker. You can see the Tee inside under the back of the venturi. The bullet helps a little bit. I may try a couple pieces of closed cell foam under each calf with an inch gap in-between that would reduce the amount of water a bit.

Reivers Dustin Aug 26 #29965
Great vid James. But dang! how long are your legs? Are you like, 90% leg and 10% everything else?

That chuckle at 1:40 is perfect. That's just the way this boat feels when it gets those freebie rides.

rd

Tom Halsted Aug 27 #29969

Wow, this sure flexed some emotions and ideas from folks!

The attached pix show my hokey “fix” (which worked even better, when I added a bit of tape to seal the insertion point and hold it in place).
And I did just email Kai, to get his take.

-Tom

Tom Halsted Aug 27 #29970
Kai's response, plus some pix of their add-on mod that looks like a better version of my tweak:

We recently changed the drain scupper to a bullet drain system.
What was happening in the past with the scupper is some were positioned correctly for flow and others not. We just finished up a a small modification something like what you did but it is shaped to fit tightly with the current bailer.
I’ll see if I can get an image of it. This will be the quickest easy fix. Putting a new scupper with billet or drain system in would take a little bit of work.

I'm also asking if he'll send me one of his slip-in option.
Or, maybe I'll grind on some PVC piping or other plastic, to replicate their version.

OPS Aug 27 #29971
Or

https://www.oceanpaddlesports.com/store-categories/Bullets-CARBON-p79286407

DeAnne Hemmens
Ocean Paddlesports

Tom Halsted Aug 27 #29972
Good lookin' bullets!
Thanks, DeAnne.

FYI, Kai says he's sending some of his extensions to JD, for his “Service Territory”.

JD, let us know when you can toss some our way.

Thanks for the group-think on this occasionally draining topic…

beau whitehead Aug 27 #29974

If you can source an old shaft from a carbon SUP paddle, I've had great luck shaping replacement scupper shields out of those in the past as well.

OPS Aug 27 #29975

I also have some hoods that are left over parts from years of this business. If you order bullets I’ll throw one or two in for free. Might work might not.

DeAnne Hemmens
Ocean Paddlesports

Tom Halsted Aug 27 #29976

Plan B from a hand-ground section of PVC pipe (inserted and secured with clear tape).
It may be clunky, but I'll try it out this weekend and see how it drains.

Duncan Howat Aug 27 #29982

Tom 2 other points. 1. A little water weight down low in the boat could give you added Stability in 2 to 3 foot cross chop. 2 If you just keep your speed above 6.9 -7.2 and above -waters gone. Specially downwind when it counts. Flex Boy

Tom Halsted Aug 27 #29983

Duncan, I agree and it all works fine if it's just a little water weight down low. But when the boat doesn't drain it often fills up under my bum. And that's a bit too much water for decent stability. So, draining faster should help

Dennis Mowry Aug 27 #29985

I purchased a bailer from Nelo for $50 and got a price from Sterling's Kayak for $1200 minimum to have it installed. I'm sure they would do a nice job.

Checking other options.

I'm considering just drilling a hole straight down from where it goes in, then install a hood and bullet directly underneath. Then pull out the tube it flows through which exists about couple inches back. Cut off the existing hood and patch all that up. Do some painting.

Then again maybe just add the Venturi myself, starting on my Vega rather than the Flex Pro.

I'd better wait though to see what Kai comes up with.

Hopefully see you in less water,
:D

Vega Scupper Q/A
Tom HalstedAug 28 #29987

Current best draining tweak is my original cut up card one.

The carefully hand milled PIVC pipe scrap one didn't fully drain, even at 7.5mph.

When I went back to the cut up card, it fully drains, starting around 6.3mph.

Maybe the fact that the card extends down into the drain at an angle is a factor.

Still tweaking…

David Scherrer Aug 28 #29988

And I assume it needs to be a Barns and Nobel card……

Jon Denham Aug 28 #29989

Adding carbon bullets from DeAnne to the Swordfish definitely made it start to drain at lower speeds. It starts draining at about 3.5mph. Before adding them is was prob 4 or 4.25 mph before they started to drain noticeably. YMMV.

James Schulz Aug 28 #29990

I tried a trumpet flare shape and it worked crazy well. I used the flared neck of a plastic simply orange juice bottle. I don’t think a straight extension will do much. I think that there needs to be an angle increase or flair at the end existing venturi. Just lily dipping and the water was down to the top of the drain hole and after ten strokes the footwell was dry. Duncan’s right, it’s a different boat without the water in the foot well. A bit tippier but much lighter. Upwind it’s a drier ride. Going up the waves the bow rides higher so less water comes in and much less bow slap after going over the wave not having all that water in the foot well. Much improved. I made the turn about a third of a mile west past the Steamboat Flats marker in WNW 15 mph avg wind speed against a flood tide. Saw the first wave, took three strokes and started hearing the venturi sucking air. Tomorrow should be a winder day at Jetty so more testing. In another month it will be Nuketober! Practice your remounts!

Jim Schulz

Tom Halsted Aug 30 #29995

Yes David, it needs to be a B&N card with exactly $2.58 left on it.

And thanks, for the flare idea, James.

I will try feathering the trailing edge of my PVC pipe version to see if it makes a diff.
And I think we should try tuning these various options to see if we can hit specific notes when they start sucking air.
Combine hydrodynamics with some acoustic/musical engineering….

Tim Niemier Sep 16 #30104
Vega Scupper group,

I think what is going on here is that the water has to “separate” from the scoop that draws the water out. I imagine that they buffed the edge of the scoop round which didn't let the water separate. I put a tiny bit of weatherstrip only about 1/16 of an inch high and it drained like crazy. I think some thick tape will be more durable. I like the insert behind the scoop and think that will help also.

On one of my boats I added a one way valve that worked really well so that when you stopped the water didn't come back in.

Cheers
Tim Niemier

Paul Reavley Sep 16 #30105
Thanks Tim - can you show us where you put the tape with a photo?

More than you wanted to know - surfski.info - one of the additional advantages for the bullets mentioned is that they also reduce overall boat drag a bit.

(Ed: 2025 - probably going forward Kai Wa'a is including bullets with their scuppers - they are definitely doing it with the Arc)