Dockside Water Supply Hookup

[Valor323]

Hi,

Recently spent a week on a friend's SO440. He has a port on the rear of the boat to plug a dockside water hose into, that pressurized the entire system and didn't use the pumps or the water in the tanks. It was fantastic to take a long shower without worrying about your onboard supply.

I looked at the plumbing schematics in the 440 manuals, and it would appear as if the dockside water hookup port were plumbed directly into the cold-water supply at the aft transom shower and back feeds the entire system from there? Does anyone have any knowledge of how this is plumbed? Would a water pressure regulator of some sort be required? With the exception of the actual port, no other parts were itemized in the manual. Anyone?


440 plumbing.pdf (792.16 KB)

[loredo]

There is a pressure regulator installed and then it's exactly like you say fed into the cold water line of the transom shower.

Simple and works great but... there is often a but, isn't it?  The "problem" with this system is that when you leave the boat the municipal water remains in all hoses. This has led in my case to stinking water in the whole system when I returned to the boat three weeks later. Stink that I'm fighting with since then (but that's another story).

Depending upon your use-case it could be heaven or it could become a problem.

Hope this helps taking a decision.

[Tafika II]

If you have a watermaker, chlorinated water is a big NO for the system This freshwater "city" intake would also have to be filtered

[Valor323]

Sept 6, 2023 9:47:02 GMT loredo said:

There is a pressure regulator installed and then it's exactly like you say fed into the cold water line of the transom shower.

Simple and works great but... there is often a but, isn't it?  The "problem" with this system is that when you leave the boat the municipal water remains in all hoses. This has led in my case to stinking water in the whole system when I returned to the boat three weeks later. Stink that I'm fighting with since then (but that's another story).

Depending upon your use-case it could be heaven or it could become a problem.

Hope this helps taking a decision.

Why would dockside water stink compared to what's in the tanks? Aren't you filling your tanks with dockside water?

[Charlie-Bravo]

We treat our tanked ‘dock side’ water, so it remains ‘ok’ if not exactly fresh , if untreated water from the dock sits in the pipes for weeks it could well stagnate and whiff.
I would be very quick and easy to flush the system through with treated tank water before leaving , removing the issue.

CB

[loredo]

"Why would dockside water stink compared to what's in the tanks? Aren't you filling your tanks with dockside water?"

I add this to my tanks at every fill : www.svb24.com/en/yachticon-aqua-clean-without-chlorine-liquid.html

Without any additive the dockside water will deteriorate quickly.  Even more so when it's in hoses and warm weather. With the aqua clean water can sit in the tanks for months without deteriorating.

"would be very quick and easy to flush the system" 

nope, not on my boat.  Too many faucets / showers / WC (fresh water flush)...

would need to be flushed to return to the treated tank water.  AND the water heather!  Any idea how much water it takes to flush out the untreated with treated water? NOT quick nor easy.  

YMMW!

[rene460]

To address the original question, our boats have a low pressure system, not designed for the pressures that can come from municipal systems, and if a shore connection is installed, it should definitely include a pressure reducing valve close to the the water inlet.  Then it would be connected at a convenient point on the discharge side of the pump.  The transom shower hose piping would certainly be a suitable section to join in.  Any place after the pump discharge would not supply a water maker inlet so should not be an issue.  The pressure reducing valves are in my experience always included in land based caravans which are fitted with the pressure reducing valve, and the valves are available at caravan parts outlets.  It’s not easy to measure the pressure of a municipal supply as it varies greatly depending on how much water is being used in the area, and may even vary seasonally.  So could be particularly high at night for example.  Better to just pipe in a pressure reducing valve.

Municipal water supplies are normally quite adequate quality, though some may contain enough extra minerals to affect taste.  And as has been mentioned, most of us fill the water tanks from the municipal supply, and leave the water in the tanks between visits.  But there are exceptions and these are the reason some people keep at least two tanks separate and only fill one if at a new site, until the quality is proved satisfactory.  You almost certainly know how you go with your home base marina, the issue can arise when you are away from home, particularly if you find your self in a remote place using tank water and without the usual quality supervision of a larger municipal supply.

Some forum members have had occasional problems and needed to use a tank cleaning product, but my impression is that it is only needed occasionally, and suitable products are definitely available at chandlers and also at RV/caravan parts outlets.  I carried a supply for thousands of km in the caravan and never used it.

Our boat was always at the same home marina, and water was always ok, never had to do a tank clean.  With the land based caravan, I have travelled much more extensively, and connected up at some very remote locations without any issues with the tanks or the piping.

rene460

[Valor323]

Thanks for all of the info guys. It's much appreciated!

[jy51]

As a water-maker owner and user throughout the summer cruising months, I addressed the problem of chlorinated water in tanks by installing two 10 inch filters in the dockside water system. A charcoal filter and an anti-scale filter. When filling the water tank I use the filtered water via my deck wash hose.  I also only ever use drinking water grade hose pipes.