The Offshore Voyaging Reference Site

Install A Wash-down Pump—And Save Money!


Want to save a bunch of money?…I mean really big money?

Buy and install a really good deck washdown pump.

“Huh? OK, now John really has lost his marbles”, I can hear you say. But read on, this piece of gear could save you thousands of dollars, pounds, or euros every year.

The reason is that in cruising grounds where muddy bottoms predominate (most?), one of the worst chores is cleaning the anchor rode off with a bucket, particularly if said rode is chain.

So picture this: It’s the end of a long day. There’s a good anchorage but there is also a marina not far away. What are you going to do?

We have to be up early and gone in the morning and cleaning the chain means half an hour earlier out of bed.

But that marina is $3.00 a foot so it’s going to cost us $135 plus tax!

I know, but my back hurts and bucketing kills it.

Oh, OK, just this once.

Wait, it gets worse:

And since we are at the marina anyway…well, we might as well have a drink at the bar.

And later…

I’m pooped and don’t feel like cooking, let’s have dinner at the restaurant.

By the time you get going in the morning, your credit card has taken a $400 hit.

And pretty soon, despite the best intentions to always anchor out that you had when you started cruising, checking into a marina, or picking up a mooring, becomes a habit. A habit that can easily cost you five to as much as ten thousand of your preferred currency a year!

But, if you had had a good deck washdown, none of this would have happened.

There’s More

Of course, having a decent deck wash is only part of making anchoring easy. You need to put a whole system together that includes:

  • An anchor that sets easily and that you can rely on not to drag.
  • An anchor locker that stows all your rode without the need to hand flake it.
  • A powerful windlass that works.
  • A bow roller that lets you safely stow your anchor for sea by simply tensioning the rode and locking off the brake.

You can find out about all of that in our Online Book, Anchoring Made Easy.

The goal here is to get to the point that anchoring is little more trouble and aggravation than parking a car, as it is for Phyllis and me.

I know all of this sounds like a lot of work and expense, but when compared to marina charges—over 10 years, say 50,000 to 100,000 of your preferred currency—building and learning to use a good anchoring system becomes the deal of the century.

Tips For Washdown Pumps

Here are some tips for buying and installing a good deck washdown pump:

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Scott Flanders

We tee off the water maker sea strainer. We found a couple tricks that help. From the enginroom forward it is roughly half the length of the boat. It pays to have a 19mm/3-4″ hose that runs forward instead of the usual 15mm/1-2″ to increase the flow. Next, the usual hose bib is very restricted internally. It must be full-flow as is the connection to the wash down hose. Hose nozzles themselves have different flow rates. So it’s not just the pump. We use a Shurflow Blaster pump without the usual restrictions and it works well. They are relatively cheap and rebuildable.

Now we’re coastal cruising in the Chesapeake where there is Lotsa mud so having a good wash down is imperative.



Hi Scott,
I second your concern about flow restriction.. The first thing I noticed about the installation on Morgan’s Cloud was the tight 90 degree hose bib bends— on one leg there are two immediately connected. Unless they are substantially over sized relative to the capacity of the wash down pump it will only be delivering perhaps 80% of its rated output.

Secondly, the plastic 90 at the heart of the system may in fact be Schedule 80 CVPC, but similar fittings that your local marine supply sells will be much weaker. In which case I wouldn’t want loose gear or misplaced feet anywhere near it—. And on that topic I know of two sinkings during last winter’s cold snap on the Chesapeake that resulted from plastic thru-hulls or fittings freezing.

Pat Synge

It would be interesting to know what kind of ‘plastic’ thru-hulls you are referring to. There are so many ‘plastics’: each with different characteristics.


Hi John, I’m a machinist and have made thousands of different hydraulic fittings and threads up to 1 metre diameter nuts etc. We ordered Forespar Marelon fittings for all below water fittings and deck fills on our custom aluminium yacht, when they arrived they had pretty crude threads with casting flashes and measured 1mm out of round. I know if you do up a taper thread with goop they would probably seal, but relying on goop to cover for rough workmanship(although not uncommon) is not what i pay for. They where slightly offended that i measured their product up and rejected it but gave me my money back. I did use their deck fills and they have started to go from black to chalky white after 2 years. Check out the Kiwi brand TruDesign. They are certified, have better attention to detail, superior internal flow, nice threads and a good range of fittings. Large ball valves can be quite stiff but the trudeign ones on our stand pipes and under water line fittings are still silky smooth.

Michael Quiriconi

Groco makes bronze threaded pipe nipples, their PN-Series.


Great post. Totally agree making it easy to anchor is key. With a good system it’s actually much faster and easier than docking – no dock lines, fenders, and power hookups to fiddle with on arrival and then put away when leaving.

We’ve been using the larger Johnson Aqua Jet pump with integrated pressure switch for a washdown pump and it gets the grime off the chain and has lasted through 3 years of frequent use. We cruise full-time and anchor out most of the time. We use the same model pump for our freshwater system, which means carrying one spare pump covers both systems. Another way to save on these kinds of pumps, regardless of brand, is to buy the spare for the pressure switch. When they fail, it’s often the pressure switch not the pump itself. Easy to swap out if you have one aboard, and much less expensive.

In the same vein, another way to save money with your washdown hose is to plumb it so that you can throw a valve to two to change the source to fresh water from your tanks. That makes it super easy and fast to give expensive foredeck jewelry like furlers, windlass, and blocks a quick rinse and reduce corrosion while away from dockside hoses. Matters even more in warm climates. No need to go crazy and wash the whole foredeck. A couple gallons will clean the expensive stuff and help it last longer. Just make sure you switch the valves back to salt water or next time you raise anchor your chain will be the only one aboard having a nice fresh shower.

Dick Stevenson

Dear John,
For most of the cruising grounds where Alchemy has spent time, a wash down pump is as important as indoor plumbing to the head. I agree with all your points and have a couple of further to add, unrelated to saving money, but relevant to those considering a wash down pump.
Chain will last longer when able to drain and dry, dirty chain will retard this happening.
If you are in a smaller boat, like Alchemy, and sleep in the forepeak (connected to the anchor area), then it is best to get off all bits and pieces of seaweed, mud and sea creatures that adhere to chain and will produce a smell. Clean ground tackle helps maintain a sweet smelling boat.
In areas where there is little rain or dew, it is often hard to keep a boat clean. A deck wash can produce lots of water for cleaning (buckets over the side are just work) and is especially nice just before an expected rain storm which, even if brief, will wash away salt and leave the nice clean decks behind.
For chain, the nozzle is important as is the pump, the ability to get a sharp stream is not easy on some nozzles.
If you wish for double duty, and what boat owner does not, consider a salt water wash down spray nozzle at the galley sink: easily “Td” into a wash down pump set up. This is a huge water saver when in clean anchorages for dish washing and should not be neglected as a good aid in fire fighting as it can move a lot of water.
I have often looked at the adverts for the Groco wash down kit with envy (less so now with your frequent breakages). Our pump came with the boat, is 15 yo now and survived washing down the anchor & chain many thousands of times, maybe in 5 figures by now. It is a Shurflo Blaster, 45 psi, 3.5 gpm, pn 2088-534-244. More gpm would be nice, but I would not deem it essential. It just takes longer. Nozzle tightness of spray is more important in my judgment.
My best, Dick Stevenson, s/v Alchemy

Pat Synge

The all bronze custom machined manifold is great but…..why?
Modern plastics are reliable and strong (ie Marelon) and you have a valve you can close in the unlikely case of a leak or breakage. After all further along the system you are relying on PVC and ‘rubber’ hose.

Personally I would question why you are using bronze fittings at all aboard an aluminium boat but that’s another can of worms.

Careful with those unguarded hose clamp tails.

Regards, Pat Synge, Adjo Akama


Ciao John,
i might be wrong, but in my understanding the sea water inside the seacock acts as a wire so the circuit

Bob T.

Groco should get an award for finally solving the close nipple issue with their excellent quality cast bronze nipples. Life is much better now. Reasons for bronze raw water fittings; heat, be it fire or just a failed impeller. Hot water will turn plastic plumbing to something resembling a pretzel pretty quick. Also I have found the non bronze ( be it Marlon, PVC, Nylon) will over time shrink away from its metal counterpart, especially on the engine compartment.

Dick Stevenson

Why worry about unguarded hose clamp tails? The good ones, and these look like AWAB, are not sharp at the end. Admittedly, aesthetically, the ones on the 1.5 inch hose are a little long, but when you are doing projects without a chandlery next door, it is better to have in stores, hose clamps too long than too short. It could be argued that it will catch on something and get kinked, but even then the kink should not compromise the function of the clamp: maybe make it harder to remove. I know some manufacturers give little condoms for the ends of hose clamps (usually cheap clamps they provide) and that you can buy these condoms, but I have never seen the point for good hose clamps and have no wish to provide small stuff likely to fall into the bilge and clog things.
Thanks for your thoughts,
Dick Stevenson, s/v Alchemy
Ps. Since we are in the realm of giving John suggestions, I would want him to consider the hose lead between the seacock handle and the valve itself: at minimum I would suggest a thick wire tie securing the hose to the seacock to prevent chafe (not likely but maybe) and to ensure that the valve handle could never be interfered with. If hose length allows, better maybe to lead behind the seacock.

Marc Dacey

Dick, I have found that self-amalgamating tape (, sometimes called “plumber’s friend” or “fix-it” tape for its ability to stop or retard a leak while one figures out the proper solution, can make for a neatly secured tail on an overlarge hose clamp. You can bind them fair with a small “X” of tape over the offending tail, and still have access to the tightening bolt. Best of all, you can reuse such tapes for this kind of securing job more than once. Good points concerning the wire tie on the handle.

Pat Synge

Quite right, Dick, I was nitpicking.
However, I’ve had a couple of nasty scratches from clamp tails. It’s easy to fold them in hard enough to stop them being a danger while not shortening them or making them too hard to undo.

Terje M

A few simple questions:

– I like to have as few intakes as possible. Would you recommend a separate water intake or would you be happy to share a water intake with the generator, water maker or the water cooled fridge? For operation separate intakes might be easier to operate and maintain. I really don’t like making holes in the hull!

– How power full is this pump? Can you use it for other purposes? Can you used it to prevent unwanted guest to board you boat? Can you use it is a fire situation on-board your own or even boat next door?
– Would it be sensible to use this pump as a third backup for the bilge pump? It should be possible to fit a valve where you can close of the seawater intake and use the pump as a second or third backup for the bilge pump.


Dick Stevenson

John may have different or additional thoughts, but for sure you can use it as a fire “hose”. I think of our sink salt water spray as exactly that (it is “T”ed to our deck/anchor wash down pump) in addition to doing dishes and it is well placed near the stove. Same for the deck wash hose for any fire it can reach. Mine sprays only 15-20 feet so it would be limited by range to be helpful to other boats on fire and if I was that close, I would be more likely to be thinking about getting Alchemy a safe distance away.
I would not hesitate to share an intake with most any item as long as you could be sure you were not overwhelming a genset pump (or other system) and starving it of water. You only use this pump for short periods, mostly when upping anchor when just the propulsion engine is going.
I would not consider it as much help as a back-up bilge pump. Too complicated a set-up for too little gain: 3 or even 6 gpm is not much and the set-up with strum box, strainer, maybe larger exit hose, just would not be worth it.
I hope this was helpful,
Dick Stevenson, s/v Alchemy

Dick Stevenson

John, I believe the plastic through hull material is Marelon. Dick


Re. fire fighting:
Yes, a good washdown pump can (and should) be set up so that it can double as a fire pump if needed.
You do need to *think* before using it as such, though. Do not attempt to fight a fire with water if the fire is electrical or liquid / grease based – this includes most galley stove fires. (More on fire control here.)

Dick Stevenson

Dear Marc,
Sorry for the delayed response. We have been traveling. Nice idea about covering the ends of hose clamps with a couple of strips of self amalgamating tape if you find them sharp. The one (and only) self-adhering tape that I have found that works as advertised is 3M 130C (Scotch® Linerless Rubber Splicing Tape 130C). In addition to self adhering, it has some adhesive on the back that solves the problems of the tails coming loose and mis-behaving. I use it for anything which has to be watertight and it has never failed me. I am less than skilled at using shrink tubes over electrical connections. Either they are too big (and do not shrink enough when heated), too small to go over the terminal after crimping or I fry them in the heating. This 3m tape is great at repairing those errors or just using in the first place. I got my first few rolls at Brion Toss Rigging and they have lasted a while.
My best, Dick Stevenson, s/v Alchemy

Nathan Bossett

For washdown, I’m considering skipping the throughull or other plumbing: Mount the pump in the bow locker, suction from a length of hose that can be tossed over the side when needed, and power it from the same large-breaker’ed circuit powering the windlass. There would be a separate switch/breaker too.
Are there any obvious problems with this arrangement? If the height to prime is an issue, the suction hose should fit through my bow locker drain.

Dick Stevenson

Nathan, I agree with John about the vulnerability of the pump stored in the bow locker. Given my history with pumps and plumbing (not very good or skillful), I would also be concerned with priming the pump repeatedly, air locks etc. all things that have plagued me in the past. A mantra for me in plumbing/pumps is to get it going and then never let it run dry or empty out.
It should be possible to find a place to “T” in without adding a new thru hull, even if the run is from the galley say to the bow, or a forward head if that is your boats layout. If galley, have it do double duty with a galley salt water spray.
Dick Stevenson, s/v Alchemy

Nathan Bossett

John, Dick,
Thanks. Keeping the pump always primed would be nice; I’m less concerned about the damp so long as I seal the electrical connections properly.
I could T off of the head inlet and punch a hole in the bow locker for the hose hookup (presently a watertight bulkhead from the V berth) or pass a hose through the head hatch when in use. I generally don’t like punching holes in things that are watertight.

The other options are the engine room and the galley. There’s presently no saltwater piping to the galley, which would be nice to add for other reasons. That would be a longer hose to drag to the bow, but it’s closer to midships so for an overall washdown line that’s the shortest overall length to reach anywhere on the deck.
And that leads me back to the engine area anyway, where I have a spare throughhull sitting already- it was intended for a watermaker.

Victor Raymond

John, Good point about keeping the circuit breaker off when not using the salt water pump. The two times I did not heed this advice I did indeed almost sink the boat. First night out, stormy night, new boat etc. wasn’t pretty. Woke me up though about how quickly things can go south. Both times it was a PVC fitting that had disintegrated.
I am not sure if we have the Surflo or Flojet model in 24v but it has enough power to get the mud of the chain and me wet. Naturally we carry spares of all pumps just in case.
The wash down pump is in the engine room which is fine but it means a long run to the bow which is not so good as there are plenty of bulk head fittings which is what caused the issue the first time. The system is set up with an expansion tank like a freshwater system since it is also plumbed to a faucet in the galley and was valved to the cooling system on the old AC refrigeration system (which has been replaced not because it didn’t work but because I hated the complication.)
Needless to say I don’t like the idea of being able to pump salt water into a boat. Other than a hatch it is the only way it can get in. If I had the pump in the bow it would be in a self draining locker so any leaking issues would be a waste of power but never life threatening. Anyhow perhaps a future project.
Thanks again for making us aware of the issues and solutions to keep us safer.

Dick Stevenson

Victor, If simplifying, you might consider getting rid of the accumulator and its attendant fittings. We have run our pump running a wash down nozzle and a galley sink spray for years without an accumulator.
Dick Stevenson, s/v Alchemy

Victor Raymond

Thanks Dick. I will put that on my todo list. I could build another boat with all that I have removed and thrown out. The simpler the better.

Jim R

Do you have fresh water access on deck or only salt water?

Stéphane Perron

Hi John,
I can add some meat to your money saving argument with our latest mishap.
We were anchored in a muddy bottom just a few hundred meters from a marina. When we retrieved the anchor it was covered in thick mud and so was the last few meters of chain. We started using a bucket to wash the chain as it was coming, but the process was slow. Since we had to go to the fuel dock before getting under way, we decided to just pile the remaining chain on deck and wash it at the dock.
After docking and visiting the office to have the fuel pump activated, I get to the boat, unscrew the fuel cap and step on dock to get the pump nozzle. Unbeknownst to me, my wife is using this time to finish the chain cleaning job, and she is just starting to poor buckets of water on the thick mud pile on deck. Well, guess where all this mud is flowing and guess where the designers have had the bright idea of placing the fuel deck fill? Arrgghhhhh!
We ended up having to spend the next night in the marina and hire a professional (very expensive) fuel polishing service to remove all the mud from the tank.
Now, I know that it was pretty stupid and easily avoidable, but I will move the deck fill to a higher spot and install a wash down pump in the future…

William Murdoch

A major part of a wash down system not mentioned here is the nozzle on the end of the hose. I mostly see people using garden hose nozzles. Occasionally, I’ll see someone with a washdown (sweeper) nozzle on the end of a short length of 1/2″ PVC pipe screwed to the end of their hose. That arrangement gets a powerful stream of water right at the chain. But, the best I have found is this thing which is made to clean the black water tank on a RV… . It has an on/off valve at the hose end, a 27″ wand to reach out to the chain, and a sweeper nozzle on its end mounted at 90° to cut the mud off the chain. On a perfect day I can just lay the end over the bow roller shooting down and rinse the chain off as fast as the windlass pulls it up. More usually, I knock the mud off a couple of feet of chain from one side and then from the front, bring the clean chain aboard with the windlass, then clean the next few feet.

Star Tracker

For nozzles, my personal favorite trick is is soft copper line for the nozzle. If not going built in anchorwash I take a ball valve, thread in a copper compression fitting and make a copper wand out of it. Custom made to just the right length to reach past the roller. Simply cut the end at an angle with side cutters, and tweak with pliers to have a nozzle that has no moving parts, and no fussy valves. For built in I build them like a 3 tined fork, one from the back, one at a 45 each side on a manifold of T fittings. Turn pump on, turn winch on. Mud stays off the boat and mess happens over the side and in a hurry too!
Forgot to add, this same copper washdown nozzle is great for blowing crud off deck drains, bird poop etc. But take it off and install it on a fule rated transfer pump and it’s a fuel polisher wand.

Alternatively, I purchased a Milwaukee M18 transfer pump, and swamped the impeller in it to a oil resistant one, it uses garden hose fittings but I used 5/8″ reinforced plumbing hose to a full width nipple for the intake line(won’t crush), then knockoff Flexzilla hose on the output side. It’s so much nicer than cheap garden hose and packs in half the space. Added a screened end for bilges. It and my M18 wet dry vac with gortex style filter are my most used boat tools.
I have saved a dinghy here and there with it, pumped out lockers and bilges when I didn’t want to run filth through the bilge pumps and thus overboard, and it makes an excellent washdown pump, I get hours of runtime.

Works as emergency bilge pump too.
Found out my boat neighbor in the past has used it to transfer gas which I would never suggest, and diesel which is why I replaced the impeller.

My best save so far with it was using it as an emergency cooling pump on a big Cummins diesel when the belt driven coolant pump grenanded in a channel. Pulled the rad cap, ran it as a total loss cooling system letting the bilge pump catch it. Ran approx 3 hours this way to make anchorage.

Just some food for thought on the plastic bits. In any case where I cannot find a bronze fitting, I have had almost no real issues with stainless steel. Bronze and 316 are actually pretty darn close, and I find I have less issues with 316+bronze than mystery brass+bronze. I do not like plastic fittings below the waterline, Marelon or not.
In my current boat I have steel standpipes welded in the hull, and I’m switching all plastic to stainless steel.

Further thought: I use a chart like the lower one here often when deciding mixing metals.
This also lets you decide your failure point in a series. For example I will always prefer to consume fittings inside the boat before seacocks, and seacocks before thru-hulls. If I’m going to have a failure, the farther up the chain where that failure will manifest and the more options I have to resolve it the better.

Star Tracker

Hi John,
Sorry, I should have been more clear, I would never use anything like that pump plumbed in with a thru hull. For anything connecting to a thru-hull below the waterline, I like the vinyl sanitation hose best.

The hose choices for that portable pump are based on keeping it portable, the marine reinforced plumbing water hose gives enough suction resistance on the intake side, but still coils up well. in my case I store it in a small nylon bag. Which is why I thankfully had it on board the boat where we used it over the side to pump seawater into the freshwater side of the cooling system of the engine.

Could easily leave it coiled up in the anchor locker though if it’s main use is going to be anchor washdown/deck wash.

For the specific case above of 316 to bronze, the thru-hull will go first. Not ideal, but brass is just too dangerous. Marelon I’m on the fence about still, I’ve seen two failures but perhaps they were age related.

More often the issue I have seen is people have difficulty thinking they’ve got Marelon and instead have plastic. I suppose my order of preference on anything a metal boat would be all bronze with correct threaded flange between thru hull and valve then to a fitting of bronze, 316SS,marelon,brass in that order of preference depending on availability where I needed it.

In my personal case, I will just sleep better knowing my boat is all steel, albeit at the cost of swapping out valves on a shorter schedule.

Star Tracker

Yes, I agree that that is a definite possibility, compounding that issue is the possibility of not even Marelon being used for nipples etc. While the 93 series is a much better product, it’s often hard to get stock on it, and few if any chandleries in my experience have them in stock due to cost. If you’re doing a full replacement of all thru-hulls and seacocks, then I would agree that the 93 series would be viable.
At a cost differential of 38$ per complete assembly, 195$ Marelon 93 vs 233$ All Bronze Groco, with the bronze in stock at Defender and can ship tomorrow, with better flexibility of choice for fittings on the hose side, while the Marelon is back ordered, I’d lean heavily towards the bronze.

Ramon Pla

I have no saltwater pump until a haul out; unsuccessfully went on the hunt for a portable unit.

Has anyone used a cheap $20-50 pump with a dedicated battery mounted in a splash proof case? I’m assembling one to test out – just carry the 10lb case near the bow, tie to a cleat, toss the intake overboard (or into a bucket hauled up), quick connect hose in anchor locker and turn it on.

Not too concerned about durability, just getting the job done with a quick freshwater flush at the end. No electrolysis or through hull risk.

Ramon Pla

As luck would have it, I found this full package after ordering individual components. I’m planning on mounting them in a box with a handle.

Eric Klem

Hi John,

If you follow through with your super short chain rode for the J109, you could almost get away with no wash down system at all. For years we anchored on hybrid rodes and prior to getting to the chain section, we only had a handful of times that a couple of quick tugs wasn’t enough to get the line clean enough for the locker. We probably only spent 10-20% of our time in New Brunswick and Nova Scotia but I don’t remember having any more issues there than a place like Maine although it has been quite a while. Chain is a different story though as you know well.


Brian Fry

I have been cruising the Chesapeake Bay for 8 years. The last 2 years we have been cruising South on the ICW in the Winter. While we do have a washdown pump, I have a technique which we use that (almost) completely eliminates the need for one.
We have 120 ft 3/8″ chain and 3/4″ rode besides, and a Mantus 55lb anchor.
Before pulling up to the anchor for retrieval, put the engine in reverse and throttle up like you were backing down to test the set of the anchor. This jerks the chain out of its’ pile and the muddy bottom. The links shed the mud they were holding. Now retrieve as normal, letting the anchor blade just below the waterline as the boat is driven (slowly), thus washing the mud off the anchor.
We have only needed to use our washdown once to clean the chain, as we had inadvertently anchored in a bed of tiny clams, which stuck to the chain, even the washdown had trouble getting them off.