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behind-cockpit pumps vs separates

Posted: Wed Oct 14, 2020 11:58 am
by mrcharly
I'm considering an older 80s boat that has a pump mounted on the aft deck, just behind the cockpit.

Although a high-capacity pump would be useful if spraydeck leaks, or I swim and have to re-enter, I'm not sure the utility outweighs the inconvenience.

The pump handle looks like a major snag hazzard when rolling and would make it awkward to do a cowboy reentry (the boat has an ocean cockpit).

Re: behind-cockpit pumps vs separates

Posted: Wed Oct 14, 2020 12:28 pm
by Owen
Pumps behind the cockpit are next to useless, you'd be as well to take it out and blank off the hole.

Re: behind-cockpit pumps vs separates

Posted: Wed Oct 14, 2020 12:35 pm
by Chris Bolton
I had a boat like that (in the 1980's). It was almost impossible to use the pump when sitting in the boat, unless it was flat calm, so you needed somebody to raft up and operate it - and if you have help, there are better ways now. The boat I had during to 1990's and 2000's had a foot pump of my own devising, plus a separate hand pump, and my current boat has a built in electric pump (and a separate hand pump).

Re: behind-cockpit pumps vs separates

Posted: Wed Oct 14, 2020 1:16 pm
by mrcharly
OK, thanks. That is useful input.

If I get the boat I might look at converting the place taken up by the pump into a day hatch.

Re: behind-cockpit pumps vs separates

Posted: Wed Oct 14, 2020 1:55 pm
by P4ddy
Electric pump...dam your posh

Re: behind-cockpit pumps vs separates

Posted: Wed Oct 14, 2020 2:03 pm
by mrcharly
lol I used to crew for some fast people in multi-day river races in Australia. They had electric pumps back then (over 30 years ago). Saved on stopping paddling when they needed to pee.

Re: behind-cockpit pumps vs separates

Posted: Wed Oct 14, 2020 3:20 pm
by Chris Bolton
Electric pump...dam your posh
It was a standard option when I bought the boat

Re: behind-cockpit pumps vs separates

Posted: Wed Oct 14, 2020 3:39 pm
by MikeB
The hand pumps being discussed were initially used on the likes of the Nordkapp Expedition and were intended to be used either rafted, or by someone else in the raft beside you. You'll never successfully clear a flooded boat with one of them while pumping solo.

Re: behind-cockpit pumps vs separates

Posted: Wed Oct 14, 2020 7:39 pm
by SJD
Looks like my experience with deck pumps is different than the opinions expressed so far. I have owned two Nordkapps, an'86 and a '91, both with Chimp pumps mounted behind the seat and right of centerline. Both worked fine and would easily empty the cockpit. I did make two modifications in order for the pumps to be more satisfactory and useable. First, I affixed the suction hose to the hull just forward of the seat using a foam cradle and bungee cord. Second, I fabricated a new handle which was low profile and had a roughly 30 degree bend. The goal was to have the handle out of the way but still be easily reached for pumping while seated in the cockpit.

I should also note that I use to own a '92 Anas Acuta with the same type pump mounted in the same position. Contrary to the experiences in the Nordkapps, this pump was junk. There was a leak somewhere that would greatly reduce suction. I never did find the reason or fix the problem.

Re: behind-cockpit pumps vs separates

Posted: Wed Oct 14, 2020 8:42 pm
by Jim
I had a boat like that until last year, but I never had recourse to find out if I could use the pump solo in anger. I rigged it up in tandem with an electric pump years ago, which again was never used in anger, I think both have been used on the beach after swamping getting out in rough conditions before carrying the boat any further, but never needed whilst afloat.

Day hatch conversion and electric pump is a far batter plan. I am still using a sealed lead acid battery for my pump (I have had my new boat a good few years now), if I build another one I will find something more modern and lightweight, lithium-ion probably. Actually, you can probably buy a system off the shelf these days if you don't fancy trying to build it yourself.

Re: behind-cockpit pumps vs separates

Posted: Wed Oct 14, 2020 8:44 pm
by Jim
SJD wrote:
Wed Oct 14, 2020 7:39 pm
I should also note that I use to own a '92 Anas Acuta with the same type pump mounted in the same position. Contrary to the experiences in the Nordkapps, this pump was junk. There was a leak somewhere that would greatly reduce suction. I never did find the reason or fix the problem.
Possibly a damaged diaphragm - you can get rebuild kits for many of these pumps from yacht chandlers still, which reminds me - if the OP is going to take the pump out and convert to a day hatch, you might be able to get a few quid for the pump, they look archaic but some types are still used in the sailing community.

Re: behind-cockpit pumps vs separates

Posted: Wed Oct 14, 2020 10:39 pm
by mrcharly
I'm familiar with the pump type and have refurbed them a few times (used to live on a sailing barge).

They are generally reliable but very vulnerable to getting something stuck in one of the flap valves. Even a bit of hair is enough to disrupt the suction and prevent them pulling up water.

Re: behind-cockpit pumps vs separates

Posted: Thu Oct 15, 2020 6:59 pm
by seawolf856
An electric Whale submersible bilge pump with an auto water sensor built in, placed behind the seat and a LiOn battery in the day hatch is what I have. It is a bit complicated to install but great once you know how to do it and extremely useful following self rescue.

Re: behind-cockpit pumps vs separates

Posted: Fri Oct 16, 2020 8:05 am
by mrcharly
The electric Whales are less prone to blocking than the manual pumps (they have a better intake filter for starters).
What sensor did you use? Float sensors are used on boats, but they usually require a cm of water at least.

Re: behind-cockpit pumps vs separates

Posted: Fri Oct 16, 2020 5:19 pm
by pathbrae
Float sensors are not ideal in a kayak where they might end up pumping air out (and so sucking water in) in an inverted boat.

https://marinestore.co.uk/Merchant2/mer ... FQQAvD_BwE kind of thing has no float but still operates automatically.

Anothe roptiuon is the "waterbuster" type of pump - self contained and fully manual.
https://www.force4.co.uk/item/Attwood/W ... 5cQAvD_BwE

With a bit of ingenuity it can be fitted securely behind the seat in most boats. Not as convenient as a fully fitted 12v system as you need to lead the outlet hose out through your spraydeck, reach the swith etc.. but easy to move from boat to boat.

Re: behind-cockpit pumps vs separates

Posted: Fri Oct 16, 2020 5:44 pm
by Chris Bolton
My system has the pump behind the seat, with cables sealed through the bulkhead to a battery in the day hatch, and an air bladder on the footrest that operates a toggle switch in the bulkhead; press for on, press again for off. I had to put a pinhole into tube from the foot-bladder to the switch, as a warm day pressurised it and locked the switch on. I also fitted a buzzer in the day hatch, as the pump is quite quiet as I occasionally pressed the foot switch accidentally and didn't realise until I reached a quieter bit of sea.

Re: behind-cockpit pumps vs separates

Posted: Fri Oct 16, 2020 8:10 pm
by Owen
I have a Rule500 automatic pump behind the seat. The battery is in an otterbox also behind the seat. It switches on every couple of minutes, if there's no resistance it switches off if there is it carries on pumping. There is a buzz as it tests for water which can be annoying on very calm days but I don't tend to connect it then. Must admit I probably wouldn't bother with another one if I ever get another kayak, it really doesn't get much use. I still carry a hand pump just in case.

https://www.marinesuperstore.com/marine ... bilge-pump