How fast should a cockpit drain?

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2 years 9 months ago #38624 by Impala
Hi all,

I recently tested my CS Cruze's two venturi bailers. I filled the cockpit up almost to the rim and then started paddling fast (under flat laboratory conditions).  It took more than two minutes - quite slow, to my surprise. When I paddled the ski in ocean waves, on the other hand, I did not have an impression of slow drainage.
For comparison, my new own-built ski, which has hardly any hump (so is likely to take on more water than the Cruze) drains in 30 sec thanks to a very big anderson bailer.

How long do your skis need to completely drain? Can the venturis' performance be improved? They contain a kind of sieve (no idea for what), but I am reluctant to remove that.

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  • MCImes
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2 years 9 months ago - 2 years 9 months ago #38626 by MCImes
Replied by MCImes on topic How fast should a cockpit drain?
On my SF-S, I had water intrusion from both bailers so I enlarged them. Prior to enlarging I could barely fit my pinky finger in them. Their diameter was around 1/2" or 13mm. I enlarged them to 20 or 22mm.

With the 13mm holes they drained very slowly. It would take forever to drain a full bucket. Maybe 60-90 seconds at a fast clip,

With the large holes I just did a test, letting the bucket flood completely, then I took off at 80% pace on flat water. It took 31 strokes to suck air. On ocean swell when I can build speed quickly, the other night I was able to suck air in a mere 12 strokes.

I also have bullets on my ski which lowered the air-sucking speed from ~5.5mph to ~4mph, so that helps me as well.

The sieve is just so weeds and crap dont come in through the bailer. I believe you could remove it without issue
Last edit: 2 years 9 months ago by MCImes.

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2 years 9 months ago #38627 by zachhandler
I have a carbonology and the sieve housed a silicone snorkel valve to prevent the bucket filling when at a stand still. It slows back fill immensely but slows drainage a good deal too so i removed the valve. 

Current Skis: Epic v10 g3, NK 670 double, NK exrcize, Kai Wa’a Vega, Carbonology Feather, Think Jet, Knysna Sonic X
Former Skis: Epic V12 g2, Epic V12 g1, Epic v10 double, Nelo 550 g2, Fenn Elite S, Custom Kayaks Synergy

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2 years 9 months ago - 2 years 9 months ago #38630 by Atlas
The first time I ever paddled my brand new Carbonology Sport Boost LV was into a 20 knot headwind. I found the drainage to be so slow that I had a virtually full bucket until I turned around and paddled back with the wind. The drainage was better but still not great. I removed the silicon valves as soon as I got back to the beach. On subsequent paddles in very rough water I found that the plastic frames that held the valve would act as a strainer and occasionally trap small weeds that would normally drain out of my other skis. So the drainage slowed down again. That "strainer" had to go too so I got in there with a small pair of side cutters. She drains fine now. Not as fast as a DeBrito bailer but as fast as my Fenn skis.
When I picked up my Boost LV X the second thing I did (after ordering a DK rudder) was to get my side cutters out again and get rid of those PITA strainers before I even paddled the ski.

Current boats
Epic V10L Ultra, Epic V9 Ultra, Carbonology Sport Boost X LV, Fenn Bluefin, Nelo 510, Fenn XT double, Nelo 600, Expedition Kayaks Azure, Mirage 732.
Previous boats
Spirit PRS, Fenn Swordfish, Fenn XT, Fenn Swordfish S, Think Zen, Epic V10L Club, Carbonology Sport Boost LV
Last edit: 2 years 9 months ago by Atlas.
The following user(s) said Thank You: Impala

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2 years 9 months ago - 2 years 9 months ago #38636 by Impala
A thousand thanks to you guys!

Atlas, did I get this right: you removed the black plastic frame around the bailer's inlet to increase the hole's diameter (don't want to accidentally open the ski ...)? 
Last edit: 2 years 9 months ago by Impala.

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2 years 9 months ago - 2 years 9 months ago #38637 by Atlas
Hi Impala. I did not remove the black plastic inserts. I just cut the coloured plastic "spokes" of the frames that held the silicon valves. This doesn't increase the diameter of the holes. It just allows the water to drain more easily through the venturis and stops small weeds getting stuck and blocking the holes altogether. You do need very small side cutters or better still; bonsai flush cut pruners.
This is very minor "surgery". Drilling out the black plastic inserts would certainly improve drainage even more but that is obviously much more involved. I am satisfied with the drainage now and can't be bothered having to mess around with epoxy to seal up the sides of the holes if I drilled them out.

Current boats
Epic V10L Ultra, Epic V9 Ultra, Carbonology Sport Boost X LV, Fenn Bluefin, Nelo 510, Fenn XT double, Nelo 600, Expedition Kayaks Azure, Mirage 732.
Previous boats
Spirit PRS, Fenn Swordfish, Fenn XT, Fenn Swordfish S, Think Zen, Epic V10L Club, Carbonology Sport Boost LV
Last edit: 2 years 9 months ago by Atlas.

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