Loss of Power

Mar 29, 2005
50
Hunter 41 Aft Cockpit Herring Bay, MD
Shakedown cruise yesterday after a year in the slip. Bottom paint was applied a year ago, which usually lasts for two seasons. Pulled out of the slip but was only able to reach 3.2 kts. @ 2200 rpm. (56 hp Yanmar and usually can cruise at 5.0 kts @ 2200 rpm) Continued to open area, and after 45 minutes or so was able to increase speed to 4.1 kts @ much higher rpm (3100 rpm). Even with boat pointed downwind in 15 kt wind, I was only able to see a 0.1 kt increase in speed. The loss of power occurred throughout the full rpm range. Also no black smoke. I went below to visually examine the spinning of the propeller shaft. All seemed normal for the rpm. I strongly suspect the loss of power is being caused by an unusually large buildup of crud (barnacles etc) on the hull and propeller. My question is whether anything else might be going on before I go to the expense of a short haul and powerspray.
 
Oct 26, 2010
1,883
Hunter 40.5 Beaufort, SC
If I read your post correctly, you boat has been in the slip for about a year. If you reach your hand down below the waterline as far as you can reach do you feel growth and possibly even barnacles? Have diver clean your hull and prop and see if that helps. Down here in Beaufort SC it generally requires an in water hull cleaning about every 4 to 6 weeks during the summer even if you have new bottom paint. Fouling on the bottom and especially on the prop can severely reduce the ability reach rated rpm and make any good hull speed.
 
Oct 26, 2010
1,883
Hunter 40.5 Beaufort, SC
Don't you have reputable divers there who can clean the hull and prop while still in the water for a "reasonable" price ? I can't imagine that it will cost as much as a short haul and power wash. We pay about $2 to $3 per foot for a cleaning. Maybe a little more if there are a lot of baracles. You might also have something wrapped around the shaft and the diver can check for that. If its been in for a year you may need new zincs too and the diver can replace those too.
 
May 1, 2011
4,189
Pearson 37 Lusby MD
@VelaFella I got on the water for the first time this season last Saturday. Max RPM in gear was 1300-1500 - got to 2800 unloaded. Under sail, hitting 6+ knots in 15 kts apparent. I think my prop is badly fouled. According to my boatyard, they started seeing marine growth back in early May that we would typically see in early July. I am blaming it on the warm winter. I'm going in for a short haul on Thu to get the prop cleaned.
 
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Oct 26, 2010
1,883
Hunter 40.5 Beaufort, SC
@VelaFella I got on the water for the first time this season last Saturday. Max RPM in gear was 1300-1500 - got to 2800 unloaded. Under sail, hitting 6+ knots in 15 kts apparent. I think my prop is badly fouled. According to my boatyard, they started seeing marine growth back in early May that we would typically see in early July. I am blaming it on the warm winter. I'm going in for a short haul on Thu to get the prop cleaned.
Sounds right but can't a diver clean the prop? Seems like it would be a lot more cost effective unless you have another reason for a short haul. If I had to do a short haul everytime I had to have the prop cleaned down here I'd go broke faster than I already am.
 
May 1, 2011
4,189
Pearson 37 Lusby MD
@smokey73 a short haul costs $90 since that's where I dry store in the winter. The last time I got a quote from a diver to clean the bottom, he wanted $130. If the boat hadn't sat unused for three months, I don't think I'd need the prop cleaned just yet. :beer:
 
Mar 29, 2005
50
Hunter 41 Aft Cockpit Herring Bay, MD
My marina, Herrington Harbour, prohibits divers in slips. I suppose there may be environmental and safety reasons for that policy, but I suspect it has a lot to do with the fees they charge for short hauls.
 
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Oct 26, 2010
1,883
Hunter 40.5 Beaufort, SC
@smokey73 a short haul costs $90 since that's where I dry store in the winter. The last time I got a quote from a diver to clean the bottom, he wanted $130. If the boat hadn't sat unused for three months, I don't think I'd need the prop cleaned just yet. :beer:
Wow - $90 for a short haul!!! That is a bargain! Not the same situation here and since there is only one place within easy striking distance from my boat where I could get a short haul our situation is different. Not sure there is enough haul capacity to handle hauling boats every 4 to 6 weeks in the warm months for all the boats that would need cleaned. Wish I could get a short haul for $90. @kappykaplan an in water cleaning would cost about $74 to $ 111 down here.
 
May 1, 2011
4,189
Pearson 37 Lusby MD
Good to know, @smokey73 ! Normally, I'd do the short haul in Aug, but it's unbearably slow under power right now. Not to mention having to do a crazy Ivan to reverse into my slip since it took so long to get enough stern way for the rudder to bite! :banghead: :beer:
 
May 24, 2004
7,129
CC 30 South Florida
A hull can get fouled in a couple of weeks in a boat standing in warm salt water. I would start by hiring a diver to clean the bottom.
 
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Mar 29, 2005
50
Hunter 41 Aft Cockpit Herring Bay, MD
A hull can get fouled in a couple of weeks in a boat standing in warm salt water. I would start by hiring a diver to clean the bottom.
I've called the diver I used years ago. No response on either of two phones. Another problem is that my marina does not allow divers to bottom clean.
 
Oct 26, 2010
1,883
Hunter 40.5 Beaufort, SC
I've called the diver I used years ago. No response on either of two phones. Another problem is that my marina does not allow divers to bottom clean.
That really is a shame. If nothing else, arranging a short haul can be time consuming depending on what is going on at the yard. Divers down here can respond in a few hours to a few days to come by and check something out and/or clean the hull, replace zincs, etc. What do you up there if you need a zinc replaced? Can't imagine replacing a zinc or cleaning a prop is an environmental hazard. Maybe a safety hazard if they are worried about electocution?
 
Mar 29, 2005
50
Hunter 41 Aft Cockpit Herring Bay, MD
That really is a shame. If nothing else, arranging a short haul can be time consuming depending on what is going on at the yard. Divers down here can respond in a few hours to a few days to come by and check something out and/or clean the hull, replace zincs, etc. What do you up there if you need a zinc replaced? Can't imagine replacing a zinc or cleaning a prop is an environmental hazard. Maybe a safety hazard if they are worried about electocution?
Electrocution is not, to my understanding, a major concern because the water is brackish with enough salt to reduce the hazard, unlike lake and river water which has no salt. (If I'm wrong, I'm sure someone will point it out.)
 
Oct 26, 2010
1,883
Hunter 40.5 Beaufort, SC
Electrocution is not, to my understanding, a major concern because the water is brackish with enough salt to reduce the hazard, unlike lake and river water which has no salt. (If I'm wrong, I'm sure someone will point it out.)
Just trying to figure out why they would not allow divers. Maybe environmental but that would only be an issue if you had ablative paint. Hard paint should not come off with a cleaning. Prop cleaning shouldn't be a problem either. seems like maybe they are driving you to use their "haul" services. Can you move somewhere temporarily where you can get a diver?
 
Mar 29, 2005
50
Hunter 41 Aft Cockpit Herring Bay, MD
Just trying to figure out why they would not allow divers. Maybe environmental but that would only be an issue if you had ablative paint. Hard paint should not come off with a cleaning. Prop cleaning shouldn't be a problem either. seems like maybe they are driving you to use their "haul" services. Can you move somewhere temporarily where you can get a diver?
I suspect the economics enters into the equation. I'm going to look into finding another diver, and a temporary location.
 

jviss

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Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
Electrocution is not, to my understanding, a major concern because the water is brackish with enough salt to reduce the hazard, unlike lake and river water which has no salt. (If I'm wrong, I'm sure someone will point it out.)
I think you have that backwards, captain. Fresh water, i.e., no salts at all, is an insulator. Salt water conducts electricity. So, more salt, more hazard of electrocution, I would think.
 
Mar 29, 2005
50
Hunter 41 Aft Cockpit Herring Bay, MD
I fear that's what mine will look like. What was the condition of the hull? Ours was painted with ablative one year ago, but we kept it in the water over winter. We have arranged for a diver, but will require going out and anchoring because our marina prohibits divers.