Salt water collecting in engine compartment at stern

[marob]

Have a 2021 Cutwater 28 and at the stern in the engine compartment on the starboard and port side are pockets about 6 inches deep and for some reason there is salt water sitting there, more on the starboard side. The port side pocket is just below the stern thruster. Curious if anyone else has this issue and have figured out how the water is getting there. No leaks that I can see. Thank you

 

[Islandoaks]

The problem is more than likely your propshaft seal which is designed to drip seawater to lubricate and cool the propshaft. The water is then sprayed in the engine compartment from the spinning propshaft. The cheap fix is to fabricate a spray shield and install over the offending seal. This doesn't stop the water intrusion but will stop sea water from spraying all over your engine compartment. The correct way to permanently fix the problem is to install a DRIPLESS seal. I don't understand why Fluid Motion doesn't switch to dripless seals! Cost probably...

 

[it4llc]

We've got a 2020 C28 with the same issue. At first I thought the fitting for the raw water intake might be leaking a bit, until I realized the weep hole for that small pocket is right behind the raw water intake. I've also wondered about how the water gets in but assumed it was probably rain water. Your comment about it being salt water though makes me wonder and am also now more curious to hear what others have to say on this.

Re the prop shaft dripping/spraying, that is in the main compartment. The smaller compartments are only connected to the main compartment via the weep holes so that spray wouldn't be the source of water in the smaller compartments. To keep the spray from getting all over the main compartment though (it was starting to cause rust on my bilge heater) I cut down an antifreeze jug and used a hose clamp to attach it over the seal. It was a $3/15 minute fix that seems to work so far.

 

[watson1987]

The correct way to permanently fix the problem is to install a DRIPLESS seal. I don't understand why Fluid Motion doesn't switch to dripless seals! Cost probably...

While dripless probably does cost more, it also costs more for the end user to replace every few years as well. And when a dripless seal breaks before you preemptively replace it, you have big problems.

 

[Red Raven]

I have an R27 Classic which should be similar in this area to the C28. I have found a bit of water in the two pockets you describe and while I do not know for sure where it comes in I do have a few comments regarding this.

My first thought is that the water comes in from the compartment below the bench seat above. On the R27 Classic there is a storage tray below the bench seat. This compartment has a drain in the bottom with a short hose to the space you describe. I store cleaning supplies in that compartment which often are wet when put in. I have always assumed the water below is from these items. It is also possible some spray could be getting into and around that compartment. Perhaps the C28 has a similar compartment with drain.

Second, and more concerning, is that the stern thruster motor is heavy and unsupported. I found that on our boat there was a bit of movement of the motor relative to the transom. The thruster bolts were tight but I could still get a bit of movement. No leaks but enough movement to concern me. I have since added support for the thruster motor housing. While I have had not leaks from this mount I suggest you check to make sure as it could result in a very bad day.

Third, if you have a stern mounted anode on the starboard side I would check for leaks around the thru-hull bolts.

Finally, there are weep holes from these areas forward to the engine room. Make sure they are not clogged. Unfortunately, even if they are clear not all the water will drain out as the holes are not fully flush with the lowest part of these areas. I regularly wipe up any water down there with a rag or a fuel absorbent pad. I have heard of others having thruster motor failures because water filled all the way to the motor housing.

Hope the helps,

Curt

 

[Toucan]

Our boat developed a small leak that I was not able to easily find. When on the trailer, I parked the boat bow-up on a driveway which had a good slope. I filled the inside of the rear section of the hull with water. There were two sources of water leaking out. The smaller leak was where the stern thruster went through the transom. The larger leak was both sides of the joint between the main hull and the separate section that contained the shaft log. There are two visible bolt heads aft of the shaft log in the bilge that I think attach this section to the hull. I attempted to remove these bolts so that I could remove the shaft log section, clean and re-bed the joint. The bolts did not want to easily unscrew and I did not want to shear them off. I had a boat yard remove the bottom paint around the joint and seal the joint on the outside of the hull.

Barry Thompson
TOUCAN, R-27 Classic

 

[FredJ]

I also found water in the wells just inboard the transom. I suspect the leak occurs while underway supporting the shaft spray hypothesis.
Inspecting after a day of use, the level was up to the bottom of the thruster/transom seal. I was unable to address the issue for a few weeks. During that time, the level was reduced. So it's not leaking more just sitting in the water.

I'd be interested to see people's shaft spray containment designs if there are any willing to share.

Fred Juhos
Blue J-2
Edmonds, WA

 

[FredJ]

I also found water in the wells just inboard the transom. I suspect the leak occurs while underway supporting the shaft spray hypothesis.
Inspecting after a day of use, the level was up to the bottom of the thruster/transom seal. I was unable to address the issue for a few weeks. During that time, the level was reduced. So it's not leaking more just sitting in the water.

I'd be interested to see people's shaft spray containment designs if there are any willing to share.

Fred Juhos
Blue J-2
Edmonds, WA