405 bow plowing

[sailtosteam]

Hi folks,
I have. 97 Carver 405 that rides low in the bow. It plows. I have tried various rpm’s, from 1200 to 2000, and I’m told the bow is way down. The spray is nearly up to the gunnels. I,ve also been having issues with water coming into the fwd bilge. Over 6 gallons during a 6-7 hr cruise. Related? I did discover a leak in the fwd A/C condensate line to the shower sump. Hopefully I fixed that. We’ll see tomorrow.
We checked the trim tabs and have them turned up as high as they will go. I’ll adjust them up before we leave in the morning in case they drift down.
The boat has 6BTA5.9 Cummins.

Thoughts? Suggestions?

Thanks for your help.
Jim

[g36]

I have a gas 405 so I can't speak to your rps with deisal but it still sounds like your trim tabs are down. How did you check their position? Did you get in the water and have someone activate them up and down? If I run mine all the way down it will do exactly what you are describing. . As far as bilge water how much dripping are you getting at the shafts seals? At rest and while moving?

[sailtosteam]

Thanks for your reply. The shaft logs drip very little. I’m always happy to see a little water dripping from them. I hit them with the IR, and as I am currently cruising the Tennessee River (yes, I know. I was hoping to go further east to Telico but stopped at Chattanooga) the temps run around 79 degrees and are cool to the touch. Rudder posts drip some water at slow speeds but I believe they drip a lot more at high speeds. This based on the accumulation in the aft bilge. I do know the rudder posts wiggle.
My water issue is at the fwd bilge. I cannot see where the water is coming in. Running with the A/C raw water valve closed seems to help. My wildest imagination thinks the water is coming back thru the A/C exhaust tubes.
I’ll run today with the trim tabs in the full up position. We checked them by holding a boat pole on them while activating the tabs. We could feel them move and hear the pump activate. When fully up and fully down the pump would stop, of course. The pumps, as you know, are at the aft end of the boat where it is the most difficult to get to.
Heading to Decatur AL today then on to Florence the next day.

Jim

[km1125]

I did have a problem once where my tabs switch was upside down, so when I thought the tabs were fully up, they were really fully down. Looks like you did test that (the same way I did when I found my problem) so that should be OK.

On the water... I'm thinking you have a scoop for the A/C water supply line and that might be forcing pressured water into the system. If you shut the seacock off and it made the problem go away (you say it "seemed to help"), then I'd look at the strainer or A/C seawater pump inlet to see if it's leaking there or one of the associated hoses. When you're normally running that seawater pump there is no pressure on those lines (actually a slight suction) so they may not leak at all, until you're underway and forcing that water into the system by way of the scoop.

How much anchor chain do you have up in the locker?? That's one common reason for boats to ride bow down.

[Cooler]

I second that question on the anchor chain. Some people like to have way more anchor chain than they need, but primarily in big water areas. Good thought but very heavy. Just to be clear, your trim tabs should be in the full up position, before you bring the hull to plain. The water in the bow will not be coming from exhaust tubes. Those tubes are aft of the stringers with weep holes. Are your water tanks full? That is a lot more weight to the mid-ship. 6 to 7 gallons of water on a 6 hr. cruise is a lot. Do you have fiberglass connectors in your exhaust system? They occasionally develop a crack and could be leaking water. Still, 6 gallons of water is not going to drag your bow down, that is only 36 lbs. er

[bud37]

In my opinion a boat that weighs almost 30,000 Lbs can handle a few hundred pounds of anchor chain on the bow...they are designed for it.

I agree about the tabs, it really does seem that the tabs are down the way the boat is acting, unless it is in the transition zone before on step. I have seen guys run their boats like that...puts up a hell of a stern wave.

Check that the tabs are up all the way and not just coming up partially.

[denpooch]

One thought on the water in the forward bilge. I have the same issue with my Mariner. When idling about or running on plane, no water in the bilge. When there are seas or 'plowing' she brings on water.
The a/c is a closed system and it is unlikely water is coming on board that route. Do you happen to have a forward bilge pump with a thru hull living up forward next to the a/c through hull? It is my contention that there lies the water intrusion. The bilge pump IS NOT a closed system and it is my guess that is where the water is coming aboard 'our' boats.

[sailtosteam]

Thanks to all for your comments.
As for the anchor rode. I have 25 ft of 3/8 chain with 200 ft of 5/8 8 Braet line attached to a 45 lb Manson Supreme. Yes, its heavy but not near as heavy as all chain.
Now, as far as weight up front, I did convert the hanging closet in the fwd berth to a pantry for the wife. It is loaded with canned goods and grocery items. We do have 3 baskets of various items on the fwd bed. Weight I am unsure of but I would guess the whole pantry and baskets no more than 150 lbs. BTW, we are currently living on the boat while doing the loop.

The fwd bilge pump is aft of the A/C raw water thru hull. I have not seen it leaking or letting water in. The water comes in fwd of the A/C raw water thru hull. Now, I did find a leak where the fwd A/C condensate line was spliced to a different hose that went to the fwd shower sump. I did a poor job of fixing that leak and need a new barbed connector. BUT, is it possible for water to be coming in the thru hull for the shower sump?

We travelled today at 1200 rpm and 10-11 mph. It “felt” like the bow was up but did not look it. No one was in front of me to verify. I had the A/C raw water thru hull closed today so only about a cup of water came in.
I kept hitting the trim tab buttons to make sure they were all the way up. I don’t know if they drift or not.
Tomorrow I will exercise the turbos and see how that affects the water intrusion with the A/C thru hull closed.

Suggestions on other things to try regarding the leak and plowing?

Thanks again for all your input.

[bud37]

The estimated hull speed for your boat is around 9 mph , using a hull speed calculator using 36' waterline length.

Considering that , you are pushing water at the speed you were travelling. That will create what you are experiencing , once again in my opinion. See what happens tomorrow when you put the boat on plane.

Have great trip.....

[Midnightsun]

Trim tab cylinders cannot drift down and remain locked down as they are single acting. They are spring loaded for return. A leak would not allow them to drift down unless the spring was gone and even then they would pop right back up once you started to move forward.