Bilge Design and Possible Modifications

D

douglee25

Well-Known Member
Jan 13, 2008
4,758
Dallas, TX
Boat Info
Cruisers 3575
Engines
Twin 7.4l
Let me start off by stating, I don't own a Sea Ray, but rather a Cruisers. Something has perplexed me from day one and I like to get some feedback.

Specifically regarding the engine bilge. The engine bilge has a pump in the very rear. The lowest part of the bilge does not stop at the bulkhead. (Edit - I later found out that it DOES in fact stop at the bulkhead) It runs forward under a false floor that supports the water tank and the waste tank. In front of those tanks there is a removable floor section which has another bilge pump. That bilge continues to run forward and stops where the front of the boat keel begins to curve up. Depending on fuel load, people load, etc the water can tend to run forward to the front bilge.

What is the reason for this design? Is it so that two pumps are able to assist with an issue? If a breach occurs in the front, water can flow to the rear and be pumped out? Reason I ask is that I'm contemplating plugging the engine bilge hole so that nothing can run forward. I don't notice any smells from water, but I want to be sure that it never occurs.
 
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First off, the bilge should be dry. If there is water there, something is leaking. The engine compartment bilge should be isolated from the forward section. Why they have forward compartments with pumps is a mystery. You mentioned a hull breach. No typical Rule pump will handle that. It's a Mayday.
 
Juliery said:
First off, the bilge should be dry. If there is water there, something is leaking. The engine compartment bilge should be isolated from the forward section. Why they have forward compartments with pumps is a mystery. You mentioned a hull breach. No typical Rule pump will handle that. It's a Mayday.
Click to expand...

It would be great to be dry... If only they didn't terminate the AC pan to the bilge. Something else I'm addressing.
 
Juliery said:
First off, the bilge should be dry. If there is water there, something is leaking. The engine compartment bilge should be isolated from the forward section. Why they have forward compartments with pumps is a mystery. You mentioned a hull breach. No typical Rule pump will handle that. It's a Mayday.
Click to expand...

Hmmm.

Whelp, I'll give this a shot with slightly different thoughts. First, I've never owned a boat that had a completely dry bilge at all times. Weather it's me being aggressive washing, rain, kids in/out swimming, I always have a little water in my bilge.

Second, there's no reason to believe Cruisers may not design their bilge compartments differently than Sea Ray.

And last, many Sea Ray's have forward compartments with bilge pumps. In fact mine has three - 2 in sumps and 1 in the actual bilge...
 
douglee25 said:
Let me start off by stating, I don't own a Sea Ray, but rather a Cruisers. Something has perplexed me from day one and I like to get some feedback.

Specifically regarding the engine bilge. The engine bilge has a pump in the very rear. The lowest part of the bilge does not stop at the bulkhead. It runs forward under a false floor that supports the water tank and the waste tank. In front of those tanks there is a removable floor section which has another bilge pump. That bilge continues to run forward and stops where the front of the boat keel begins to curve up. Depending on fuel load, people load, etc the water can tend to run forward to the front bilge.

What is the reason for this design? Is it so that two pumps are able to assist with an issue? If a breach occurs in the front, water can flow to the rear and be pumped out? Reason I ask is that I'm contemplating plugging the engine bilge hole so that nothing can run forward. I don't notice any smells from water, but I want to be sure that it never occurs.
Click to expand...

Doug, I had Cruisers 3672 that also had a small sump under the floor in the cabin and was always wet, but not from bilge water running forward, but from the AC condensation water that drained into it. It did give off a stall water order in the heat of the summer and all I had to do to combat that was to toss a couple of caps of bleach in it once in a while. I wouldn't plug the hole between the two, you want any water to flow back to the engine room. You may want to confirm the engine room pump float is operating properly, or go up in capacity size on the pump.
 
Note you have a gasoline powered boat as such I have never seen the engine room bilges connected to the cabin bilges. This would allow gasoline fumes to enter the cabin spaces. Then all electrical in the cabin space would require Ignition Protection approved devices. The engine room bulkhead is normally completely sealed for isolation.

This opening was possibly added by a previous Owner? Doe it appear factory?
If factory it would need to meet this recommendation from the USCG Boat Builders Guide.

SPECIAL NOTE:
The U.S. Coast Guard has developed the following compliance policy concerning drain holes in isolation
bulkheads:
“Any hole installed for drainage in an isolation bulkhead must be fitted with a plug or sealing device
that is intended to be in place when the boat is being used. The plug or sealing device must be
attached to the drain fitting or the bulkhead near the drain hole so it will not be lost. It must be
understood that when this drain hole is open, the isolation integrity of the bulkhead has been
breached causing a potentially hazardous condition. It is the responsibility of the boat manufacturer
to make this intent known to the consumer via means such as labeling, information in a boat owners
manual, etc.”
page 20

Such a fitting would be used only when the boat is on the trailer or blocked to drain the bilges out the transom plug.
 
Stee6043 said:
He did mention a removable floor section...don't call the USCG on him yet :)
Click to expand...

He stated "Reason I ask is that I'm contemplating plugging the engine bilge hole"
so I believe its a hole in question not the access hatches.
I would seal the hole.

In these cases the CG would go after the builder if they did it wrong not the owner.
Most of us have dealt with Previous Owners stupid ideas...

I just don't want to see something go BOOM!
 
Stee6043 said:
Hmmm.

Whelp, I'll give this a shot with slightly different thoughts. First, I've never owned a boat that had a completely dry bilge at all times. Weather it's me being aggressive washing, rain, kids in/out swimming, I always have a little water in my bilge.

Second, there's no reason to believe Cruisers may not design their bilge compartments differently than Sea Ray.

And last, many Sea Ray's have forward compartments with bilge pumps. In fact mine has three - 2 in sumps and 1 in the actual bilge...
Click to expand...
There is a problem if you have water entering your bilge.
Bilge pumps are generally for emergencies such as a hose failure. The bilge being a sump is simply poor design. Use an enclosed sump box. Why you would tolerate residual water there, getting skanky and creating other issues, is simply beyond my comprehension.
 
I have a friend with a CY 400 Express with a similiar set up. Who in their right mind would put the waste tank under the aft cabin floor to boot?

I think this is an OEM set up and not something the PO changed.

Bennett
 
Juliery said:
There is a problem if you have water entering your bilge.
Bilge pumps are generally for emergencies such as a hose failure. The bilge being a sump is simply poor design. Use an enclosed sump box. Why you would tolerate residual water there, getting skanky and creating other issues, is simply beyond my comprehension.
Click to expand...

I don't know if you directed this at me or the builder, but that's why I'm asking this question. It's a stupid design IMO and I want to fix it, that's why I'm asking the question.
 
Captsteve427 said:
Doug, I had Cruisers 3672 that also had a small sump under the floor in the cabin and was always wet, but not from bilge water running forward, but from the AC condensation water that drained into it. It did give off a stall water order in the heat of the summer and all I had to do to combat that was to toss a couple of caps of bleach in it once in a while. I wouldn't plug the hole between the two, you want any water to flow back to the engine room. You may want to confirm the engine room pump float is operating properly, or go up in capacity size on the pump.
Click to expand...

The bilge pumps work fine. They installed the bilge pumps on a metal plate that's slightly elevated off the bilge floor. I believe they do this to avoid shit getting clogged up in the impellers. It will never get 100% dry unless I vac it out.

I also have the older shaft seals that drip when under way. That's very minimal however.

I'm going to give Cruisers a shout and see what their thoughts are. The hole is factory and nothing has been modified.
 
Captsteve427 said:
Doug, I had Cruisers 3672 that also had a small sump under the floor in the cabin and was always wet, but not from bilge water running forward, but from the AC condensation water that drained into it. It did give off a stall water order in the heat of the summer and all I had to do to combat that was to toss a couple of caps of bleach in it once in a while. I wouldn't plug the hole between the two, you want any water to flow back to the engine room. You may want to confirm the engine room pump float is operating properly, or go up in capacity size on the pump.
Click to expand...

My AC condensate goes out the bulkhead and into the engine compartment.

I could definitely see them draining it to the forward bilge however on other models.

The only way to drain the AC condensate to a shower sump is to elevate the AC unit (which I do have room for). I have researched the Mermaid Condensator that uses a venturi on the AC discharge line to such the pan dry. That seems like it would be the easiest solution.
 
douglee25 said:
It would be great to be dry... If only they didn't terminate the AC pan to the bilge. Something else I'm addressing.
Click to expand...

It took me a season and a half to get all three bilges dry. Both of my AC condensate lines go to sump boxes. I do not believe my engine bilge connects to the two forward bilges. After you get your AC line connected to a sump then look close at all the exterior caulk lines. I redid all of them with life caulk, 50 feet of major caulking, but the bilge is now dry.
 
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MonacoMike said:
It took me a season and a half to get all three bilges dry. Both of my AC condensate lines go to sump boxes. I do not believe my engine bilge connects to the two forward bilges. After you get your AC line connected to a sump then look close at all the exterior caulk lines. I redid all of them with life caulk, 50 feet of major caulking, but the bilge is now dry.
Click to expand...

Did you add the sump boxes?

Where did you find your exterior caulking mostly compromised? I have maybe a couple of suspect joints at the side window in the cockpit, but no where near the amount of water that I'm vacuuming out of the bilge (my marina has covered slips too). Every area I've inspected on the side of the hull (inside) behind panels or at the higher level compartments, before it flows through the hole to the bilge, has been dry.
 
douglee25 said:
Did you add the sump boxes?

Where did you find your exterior caulking mostly compromised? I have maybe a couple of suspect joints at the side window in the cockpit, but no where near the amount of water that I'm vacuuming out of the bilge (my marina has covered slips too). Every area I've inspected on the side of the hull (inside) behind panels or at the higher level compartments, before it flows through the hole to the bilge, has been dry.
Click to expand...

My boat has a caulk seam that runs from the front windshield post all the way back then down to the swim platform and across the back and up to the opposite windshield post. Though it looked like it was in pretty good shape it actually was leaking water.
 
I spoke to the engineering group at Cruisers. They stated the boat DOES NOT have a hole from the bulk head to the front compartment according to the drawings.

I am going to confirm by removing the panel that sits between the engines and look down myself. When I bought the boat years ago, the generator had a significant oil leak. The oil film covered the entire bilge. I spent 2 weekends fully detailing the bilge, and then I spent the winter rebuilding the genset. The same oily bilge was consistent with what I saw in the forward bilge. It was a black, oily substance. It took a ton of simple green and scrubbing. I assumed the bulkhead had a hole. If it does not, I will be shocked. And now I'm completely perplexed how the forward bilge could look like it once did.

The engineer said drain the water tank to eliminate that as a source. It could possibly be coming from a leaking water line as well, however, I never hear the pump cycle.
 
Not doubting your observations but on our 440 the wall between the 2 bilges is solid. I get water in forward bilge from overflow from starboard a/c but it drains into shower sump. Pump is elevated and sits above about an inch of water. Like the idea about adding a capfull of bleach. It will smell if it sits in there for a while. Try posting on the Cruisers Yachts forum!
 
Burg guy said:
Try posting on the Cruisers Yachts forum!
Click to expand...
Unfortunately most of the brand forums other than CSR (thank you Jim) have been taken over by bots. He can try and should, if he has not, but there is no other CSR out there for any brand I have seen. The Chaparral forum is useless other than archives.

There is also a FB group for Cruisers…
 
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