Bilges for Beginners

Jonah · Mar 29, 2018

Hi everyone,

I'm on my second Grady. My first was kept on a mooring anchor, and then a lift, and whenever I put it on the trailer for the winter, I'd pull the stern plug and let the bilge dry out. I keep my current boat on the water year-round, and so I've begun paying closer attention to my bilge.

First off, I've noticed that I get a bit of water collecting in the bilge after each outing. Go figure: some splashing over the bow, or the saltwater that my anchor rhode soaked up, or some freshwater from the hose after I wash down the boat. But about how long after an outing should you expect water to STOP collecting in the bilge? Another way of asking would be: if I notice water collecting in the bilge, and it hasn't rained recently, should I be concerned if I went out the day before? Three days before? Five?

Second, let's say I haven't been out in two weeks, and the water collecting in the bilge is salty. Is that something to be concerned about? Or do boats that sit in the water inevitably collect some saltwater through their fittings, or through tiny imperfections in the hull, etc? The hull is a '95.

Third, is there anywhere that I should be concerned to find water? Obviously it seems to collect near my two bilge pumps (fore and aft), but I also found some in the house-battery compartment beneath the aft cabin. It's just in one spot, but I can't seem to figure out how/whether that water drains to the main bilge area. If no one knows what section I'm talking about, I'll post a pic.

Thanks as always.

Fishtales · Mar 29, 2018

Some things to consider and/or check...
Do you leave the boat with all seacocks closed? Is the head fresh or saltwater? The anchor rode drains into the bilge as you say maybe minimize use for a while. Cup holders may drain rainwater into the bilge. Aft scuppers if underwater could have a small leak. Hardtop mounts at the deck or windows could leak. Is your water system always pressurized? Wash down head leaking (those are known for leaking). Faucets leaking when water system is pressurized? When you wash the boat does water enter via head floor or cabin drains (if you have either)?
When you pressurize the water system does the pump occasionally pump once or twice once in a while - maybe a leak?

glacierbaze · Mar 30, 2018

The amount of water in the bilge means nothing, if you don't know if the bilge pump has kicked on, and how often. You can get a simple device that counts how many times your pump cycles. Hell, today you can probably get smart phone alerts every time it kicks on.

journeyman · Mar 30, 2018

Add to the above:
Are your through hull fittings nylon? Is so, time to change them out to Bronze. Could be cracked.
Hoses from deck scuppers to the through hulls could be leaking.
Hoses from the live-well pump or washdown pump could be leaking.
All the hoses below deck eventually degrade.
AC, Genny, head, anything that pumps, drains or holds water could be a potential leak.
Water heater - pressure relief valve, drain valve, or the tank itself could be leaking.

Spend a day and dry your bilge as best you can. Really dry. Use the brightest light you can find. Look for seepage around through hulls, transducers, sea cocks etc. Run one system at the time. Use your washdown, look for leaks. Use your live well, look for leaks. Etc etc etc. As mentioned, does your fresh water pump cycle when you're not using it? If so, open access panels and check hose clamps at T's and elbows. Any one of them could be dripping. Put a hose to each of your deck drains and check for leaks.

Lots of possibilities.

Jonah · Mar 30, 2018

Fishtales said:
Some things to consider and/or check...

Fishtales, thanks for the reply. I hadn't thought of so many ways that water could get into the bilge, so this is helpful. I noticed that the water was salty, but I should do a better test before jumping to conclusions.

I think, in another thread, it was you who recommended that I check my freshwater hoses for leaks. I make sure to release any pressure whenever I turn off my freshwater pump (it's usually off), so I don't think that could be it.

I'm going to get it bone dry today, then see what happens over the next few days without rain, hose-water, or an outing to interfere.

Jonah · Mar 30, 2018

glacierbaze said:
The amount of water in the bilge means nothing, if you don't know if the bilge pump has kicked on, and how often. You can get a simple device that counts how many times your pump cycles. Hell, today you can probably get smart phone alerts every time it kicks on.

That's a great point. Unfortunately I don't have a counter, so I'll just get it nice and dry, then watch it closely for a few days.

Jonah · Mar 30, 2018

Journeyman,

Thanks for your reply too. I'm going to start by getting the bilge very dry, then watching it closely for 48 hours, to see if water really is collecting, or whether it's just my imagination—or maybe I'm overlooking something obvious like my own water from the hose.

The main lessons I'm learning here is that there are all sorts of possibilities on a 23-year-old boat. It sounds like I could easily spend a weekend tracking down every little leak, but for now I'll start by figuring out how much (if any) is getting in when the boat just sits in fair weather for a day or two.

Fishtales · Mar 31, 2018

That will work. It isn't a big deal if you get water in there, but it is nice to know if you have a problem or if it normal activities bringing it in. You can always use some food coloring and wet specific spots and see if you notice a leak. I've seen many a boat with water in the bilge and even pumps that cycle every so often. Good luck.

Jonah · Mar 31, 2018

Hi Everyone,

One more question here: anyone know whether there exist diagrams for the bilge layout of various Grady models? I've checked in my manual and haven't found anything.

Just trying to get an understanding of which areas feed into which other areas, etc. I have a storage compartment under the aft cabin of my 272 Sailfish (which is where the previous owner put a house battery, to be closer to the SB radio and avoid any voltage drop). I can see that it feeds into the cabin bilge via a small tub through the wall, but I can't see any connection to the aft bilge, etc.

Fishtales · Mar 31, 2018

I think the owners manual is the closest thing there is. Maybe you could ask the factory if they have pics of your style boat at various points in the construction process. Most of the cavities are filled with foam or fuel tanks. The aft is obviously open and some areas for the water, waste and other things. Usually there are drains between areas but not much more.

seasick · Apr 1, 2018

One way to check if water is leaking in but being pumped out by the bilge is to disconnect the battery feed for the bilge pump. Assuming that the inflow if any is slow, you can let the boat sit for hours or days depending on things like weather etc. Make a note of the amount of water and then disconnect the fuse. Note the water level after some time and after things like hosing , deck washing etc. To start don;t wash or hose ff after the initial start of the test.

If you boat has two bilges you may need to disable the second one too if it is automatic.
One additional thought: Water often comes in through the rode locker. That locker usually drains into the forward bilge, through a drain tube under the fuel tank and into the aft bilge. The path for drainage often gets clogged and water may build up in the forward bilge. It may seep slowly into the aft bilge or may not drain at all.Also note that a wet anchor line piled up in the locker will ooze water for quite some time. The rode hatch is not well sealed and water from washing can easily enter the locker.

g0tagrip · Apr 1, 2018

I would NOT disconnect my bilge pumps from the batteries UNLESS you will stay on the boat looking for water intrusion. Do not leave your boat without the bilge pumps operational. Too many disasters could happen.

seasick · Apr 2, 2018

g0tagrip said:
I would NOT disconnect my bilge pumps from the batteries UNLESS you will stay on the boat looking for water intrusion. Do not leave your boat without the bilge pumps operational. Too many disasters could happen.

I understand your concerns but as long as the water issue is slow, there is little risk. In that case the main risk is rain, which is why I mentioned the weather concern.

The reality is that if something pops like a sea cock or a hose that feeds from a sea cock, the bilge pump won't keep up with the flow and the bilge will fill. There is as much risk without the bilge pump connected as there is with it connected and not looked at for a long period or even after a big storm. My experience is that boats often flood when the bilge has been cycling for a while and battery gets run down.

In the case presented here, the water intrusion flow is low and the first question is whether the water is getting in while at rest or under speed and in either case, how fast does that happen.If at rest, something is leaking. If at speed or after a run, the question is whether the water is entering through the hull or through a deck fitting, locker cover, access plate etc.
A slow leak from the garboard drain is also pretty common and hard to isolate unless you have a controlled environment like a dry hull, boat at rest, no rain, no hosing and no buildup in the forward bilge.

Fishtales · Apr 2, 2018

I agree. Don't disconnect the pumps. Find another way.

everwhom · Apr 2, 2018

For what it's worth, I always have a bit of water at the bottom of my bilge -- I've always assumed it was normal. I've never actually noticed the bilge pumps running except when I rinse the bilge and intentionally test them...

I figure there's always some rainwater draining down from the anchor locker, cup holders, etc.

journeyman · Apr 3, 2018

everwhom said:
For what it's worth, I always have a bit of water at the bottom of my bilge -- I've always assumed it was normal. I've never actually noticed the bilge pumps running except when I rinse the bilge and intentionally test them...

I figure there's always some rainwater draining down from the anchor locker, cup holders, etc.

Very true. The bilge pump will never pump all the water out completely. In fact, when the pump shuts off, the water in the vertical discharge leg will flow back to the bilge. But if you periodically run your bilge pump manually and there is enough water accumulated in the bilge to prime and run the pump long enough to see a flow out of the through hull, there is water intrusion.

Jonah said:
I noticed that the water was salty, but I should do a better test before jumping to conclusions.

Did you taste it? Yuk!!! Does your head use fresh water from you tank or salt water from a seacock? Either way, no water from the bilge will ever touch my lips. And I'm not even remotely squeamish, I've done a lot of things that most people would have nightmares over!

seasick · Apr 3, 2018

Fishtales said:
I agree. Don't disconnect the pumps. Find another way.

Wow

I'll bet that if you ask boaters, how many reach down regularly to check that the bilge float switch works assuming you can reach it you will find that most don't check. Yes, during winter prep or spring commingling one might check operation, we should and hopefully do check the float operation but realistically, most people find out that the switch doesn't work when they notice water buildup in the bilge ( or worse!).
I stick to my opinion that there is little risk from disabling the bilge pump for a short time and while someone regularly keeps an eye on things. One other factor to remember is that the hull if foam filled and won't 'sink'. Yes it will fill to the gunnels and that is not good but its a lot better than sinking to the bottom.

One other addition to a point I made: To test the garboard drain fitting, you have to get the bilge pretty dry at least all the way aft to be able to look for seepage. Of course if the seepage is large enough, it will be obvious but if it is small, just getting a damp finger result after not getting one is a pretty good indication of seepage.

Jonah · Apr 11, 2018

seasick said:
If you boat has two bilges you may need to disable the second one too if it is automatic.
One additional thought: Water often comes in through the rode locker. That locker usually drains into the forward bilge, through a drain tube under the fuel tank and into the aft bilge. The path for drainage often gets clogged and water may build up in the forward bilge. It may seep slowly into the aft bilge or may not drain at all.Also note that a wet anchor line piled up in the locker will ooze water for quite some time. The rode hatch is not well sealed and water from washing can easily enter the locker.

Thanks Seasick. Yes, I've now found that I have one bilge pump at the stern, and another under the cabin floor. (Also a sump pump there, for the cabin shower.) Tested both, and the auto-switch seems to work fine. Still waiting for a good time to try your test of looking for seepage, but in the meantime gave the bilges a good cleaning and got a somewhat better understanding of how they all connect. If I ever befriend anyone with a snake tool, I'll see if I can clean out all the connecting pipes/tunnels.

CJ7Rob · May 25, 2018

What are you guys using to clean you bilge? Safe to use a pressure washer under there with the fan out nozzle so its not too much pressure? Thanks

DennisG01 · May 25, 2018

CJ7Rob said:
What are you guys using to clean you bilge? Safe to use a pressure washer under there with the fan out nozzle so its not too much pressure? Thanks

You certainly won't hurt the fiberglass. But it seems like a lot of work when a good bilge cleaner and brush will do the work in less time. Heck, fill the bilge a little with water, add the bilge cleaner, go for a ride. That'll take care of a decent amount of it. If you're doing this on the water, be sure to use an enviro-friendly bilge cleaner.

Bilges for Beginners

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