I've had my current boat (Hunter 326) for over a year now, and when I have motored it this year after a winter in the water, I have been shocked how much speed I have lost. I believe it about a knot of speed; I now cruise at only 4.8 knots at 3,000 rpm. I have tried to clean off the bottom with a brush with extension, but I can't reach everywhere. However, I do think most of the bottom is clean,and I'm not jumping in the river just yet with water temperatures of 63 degrees! I also supected the Raymarine speed impeller, but I haven't cleaned that yet. (Can you really pull it when the boat is in the water?) Other boats I have had did not suffer this much loss of speed...what have all of you out there experienced? On the Columbia I NEED as much speed as I can get...this time of year there can be 2 knots of current, which can make for painfully slow progress upriver (4.8 knots - 2.0 knots = Only 2.8 knots!) Thank You! Scott
- Status
prop
Your prop is the problem it needs cleaning ,my 290 lost speed also last year and when I had the prop cleaned it came back to normal hull speed,and yes you can take the knot transducer while in water just have the blank ready but don't worry the water does not come in that fast the dept transducer seems to come in much faster.
Your prop is the problem it needs cleaning ,my 290 lost speed also last year and when I had the prop cleaned it came back to normal hull speed,and yes you can take the knot transducer while in water just have the blank ready but don't worry the water does not come in that fast the dept transducer seems to come in much faster.
Check it with a GPS first.
I would check your boat speed with a GPS before doing anything else. Then you will at least know what direction to look.
I would check your boat speed with a GPS before doing anything else. Then you will at least know what direction to look.
Don't assume...
....your bottom isn't in bad condition. I just had a survey done on a B-321, and when we motored from the dock to the haulout yard (about a 45 minute ride) we spent some time doing the "sea-trial". I could not get more than about 5.5 knots under full power (about 3200 RPM), and she sailed very sluggishly in 10 knots of breeze. Once she came out on the hoist, I saw why. The bottom was really foul as the boat had been in the water for two years straight. They powerwashed the bottom for the survey, and moved the fwd hoist strap to PW under it too, so the only thing left un-PW'ed was where the aft strap had been. When we put her back in the water and motored around again, I was able to get 7 knots at full power, and low 6's easily at 2650 RPM! There's a reason racers spend a lot of time and effort getting their bottoms absolutely smooth. Have her hauled and do a good powerwash, or hire a diver to scrub the bottom. You'll get your speed back I'm sure. Good luck! Tim
....your bottom isn't in bad condition. I just had a survey done on a B-321, and when we motored from the dock to the haulout yard (about a 45 minute ride) we spent some time doing the "sea-trial". I could not get more than about 5.5 knots under full power (about 3200 RPM), and she sailed very sluggishly in 10 knots of breeze. Once she came out on the hoist, I saw why. The bottom was really foul as the boat had been in the water for two years straight. They powerwashed the bottom for the survey, and moved the fwd hoist strap to PW under it too, so the only thing left un-PW'ed was where the aft strap had been. When we put her back in the water and motored around again, I was able to get 7 knots at full power, and low 6's easily at 2650 RPM! There's a reason racers spend a lot of time and effort getting their bottoms absolutely smooth. Have her hauled and do a good powerwash, or hire a diver to scrub the bottom. You'll get your speed back I'm sure. Good luck! Tim
Ye Old Dirty Bottom Trick
yea Scott - you'd be surprised what a dirty bottom will do to your speed. If you're speed sensitive, and it sound like you are, then maybe it's time for a bottom paint. Before hauling for painting do some tests at a couple RPMs that you're accustomed to runing at and note the speed. Try to find a place with as little current as possible, preferably no current, and note the speed, maybe with both GPS and with knot meter. If the knot meter has a dirty paddle it won't be accurate. Once the boat is hauled and the paddle wheel is cleaned it'll record differently. After the paint job - try to get the paint on as smooth as possible - repeat the tests. If there is no place with "no current" at least try to repeat the same conditions as the first test - say at slack water. I think you'll find a new paint job will put the spunk back into the old sled. Prior to a big race it's not uncommon for a race boat to be hauled and the crew "sand" it down with, say, 600 grit. 600 grit? That's polishing it! You won't believe how smooth the bottom is with 600 grit - almost like new gel coat. From your description I'd almost guarentee you a new bottom paint job is what you need.
yea Scott - you'd be surprised what a dirty bottom will do to your speed. If you're speed sensitive, and it sound like you are, then maybe it's time for a bottom paint. Before hauling for painting do some tests at a couple RPMs that you're accustomed to runing at and note the speed. Try to find a place with as little current as possible, preferably no current, and note the speed, maybe with both GPS and with knot meter. If the knot meter has a dirty paddle it won't be accurate. Once the boat is hauled and the paddle wheel is cleaned it'll record differently. After the paint job - try to get the paint on as smooth as possible - repeat the tests. If there is no place with "no current" at least try to repeat the same conditions as the first test - say at slack water. I think you'll find a new paint job will put the spunk back into the old sled. Prior to a big race it's not uncommon for a race boat to be hauled and the crew "sand" it down with, say, 600 grit. 600 grit? That's polishing it! You won't believe how smooth the bottom is with 600 grit - almost like new gel coat. From your description I'd almost guarentee you a new bottom paint job is what you need.
Current is not a problem
Even if there is a current, you can still get accurate speed information. If you're checking speed with a knotmeter, the current has no effect, as you are measuring speed through the water. If you're using a GPS, it measures speed over the bottom (aka SOG), which IS affected by current. However, if you measure your speed going in one direction, then turn around and check it going in the opposite direction, the average of the two speeds will be your speed through the water. Peter H23 "Raven"
Even if there is a current, you can still get accurate speed information. If you're checking speed with a knotmeter, the current has no effect, as you are measuring speed through the water. If you're using a GPS, it measures speed over the bottom (aka SOG), which IS affected by current. However, if you measure your speed going in one direction, then turn around and check it going in the opposite direction, the average of the two speeds will be your speed through the water. Peter H23 "Raven"
I agree with Tim -- I bet its still fouled
Even the slime on the bottom can knock off 1 Knot of speed. I too left my boat in the water and when I motored it for the first time I noticed it could make max speed. I had a new clean prop on so its not that & I know I don't need a new paint job as I just did a few coats last season and the "signal" color hasn't shown thru yet (which I wouldn't suspect in so short a time). Around here a diver charges about $1 a foot for bottom cleaning. I suggest you pay someone to do that (and tell him to do a really good job). Then take it out and see if you notice a difference....I bet you will
Even the slime on the bottom can knock off 1 Knot of speed. I too left my boat in the water and when I motored it for the first time I noticed it could make max speed. I had a new clean prop on so its not that & I know I don't need a new paint job as I just did a few coats last season and the "signal" color hasn't shown thru yet (which I wouldn't suspect in so short a time). Around here a diver charges about $1 a foot for bottom cleaning. I suggest you pay someone to do that (and tell him to do a really good job). Then take it out and see if you notice a difference....I bet you will
Thanks...
I think it is the hull, too. Here a diver wants $75 to do my 31 foot boat! I plan on trying it when the water gets close to 70 degrees...or maybe I'll get a cheap wet suit and mask...Anyway, it's probably not the prop because my boat is in the river (Columbia) and we get slime, not barnacles. I think slime will come off a prop...but I could be wrong. Part of the problem is that an 18 hp motor with a two blade prop is not enough even when the hull is clean...I could never reach hull speed anyway, but 4.8 knots is getting ludicrous!
I think it is the hull, too. Here a diver wants $75 to do my 31 foot boat! I plan on trying it when the water gets close to 70 degrees...or maybe I'll get a cheap wet suit and mask...Anyway, it's probably not the prop because my boat is in the river (Columbia) and we get slime, not barnacles. I think slime will come off a prop...but I could be wrong. Part of the problem is that an 18 hp motor with a two blade prop is not enough even when the hull is clean...I could never reach hull speed anyway, but 4.8 knots is getting ludicrous!
Another possibility
No one has yet suggested that the speedo may be acting up. There should be a calibrating screw or other adjustment in the speedometer mechanism so that the speedometer correctly reports the speed that the boat is moving. Tis happens because the water flows over different parts of the boat in different ways. If the paddlewheel is in one place on the hull, it reads one thing, in another place, a little differently. One boat I sailed on had a speedometer on each side. The windward one always read about a knot higher than the leeward one. In any case, the speedo needs to be calibrated to read correctly, probably by setting it to match with the GPS speed in an area of no current. Cleaning the bottom - and prop - and speedo paddles - won't hurt either.
No one has yet suggested that the speedo may be acting up. There should be a calibrating screw or other adjustment in the speedometer mechanism so that the speedometer correctly reports the speed that the boat is moving. Tis happens because the water flows over different parts of the boat in different ways. If the paddlewheel is in one place on the hull, it reads one thing, in another place, a little differently. One boat I sailed on had a speedometer on each side. The windward one always read about a knot higher than the leeward one. In any case, the speedo needs to be calibrated to read correctly, probably by setting it to match with the GPS speed in an area of no current. Cleaning the bottom - and prop - and speedo paddles - won't hurt either.
Not the prop
Scott, Read your last response about 18HP and a 2-blade prop... The 2-blade doesn't matter much, its the HP in front of it. We just bought a B321 with a Martec folding 2-blade, and it has no problem doing 7 knots at full throttle, low 6's at a more comfortable ~2600. The 321 has a Yanmar 3GM30F w/27 HP, though. 18 HP seems a little underpowered for a Hunter 32, but then my old First 32 had a Yanmar 2GM w/13 HP. It could not reach hull speed ever. Props are matched to HP, gearbox ratio, and displacement. They will spec a different size and pitch for 2 and 3 blade props for the exact same boats, which optimizes for each and probably doesn't affect speed in the end. Cheers, Tim PS I'm a certified diver, and if I lived near you I'd do your bottom (of your boat!) for a lot less than $75, but I live in MI...sorry! Good luck!
Scott, Read your last response about 18HP and a 2-blade prop... The 2-blade doesn't matter much, its the HP in front of it. We just bought a B321 with a Martec folding 2-blade, and it has no problem doing 7 knots at full throttle, low 6's at a more comfortable ~2600. The 321 has a Yanmar 3GM30F w/27 HP, though. 18 HP seems a little underpowered for a Hunter 32, but then my old First 32 had a Yanmar 2GM w/13 HP. It could not reach hull speed ever. Props are matched to HP, gearbox ratio, and displacement. They will spec a different size and pitch for 2 and 3 blade props for the exact same boats, which optimizes for each and probably doesn't affect speed in the end. Cheers, Tim PS I'm a certified diver, and if I lived near you I'd do your bottom (of your boat!) for a lot less than $75, but I live in MI...sorry! Good luck!
$75 is a ripoff for a 31foot boat bottom cleaning
I would look around for others. $1 - $1.50 a foot is more in line with prices and I live in a High Boat Cost fees area.
I would look around for others. $1 - $1.50 a foot is more in line with prices and I live in a High Boat Cost fees area.
Is 75.00 High??
Are you kidding me?..are we talking about the same kind of bottom cleaning?.it costs a hundred dollars here to clean a 30 ft boat and it takes a man all day long to do it...is it possable that your cleaners are not scraping the whole boat?when they cleaned mine it had been cleaned before and they only cleaned to the keel.and last year when i got the boat a man went down and found the keel was not touched and brought back up huge pieces of baracle and oysters that were in balls of 8 inches and even my water line came up when he was done at the end of the day..I was very happy..who is doing it for a 1$ a ft? Wes
Are you kidding me?..are we talking about the same kind of bottom cleaning?.it costs a hundred dollars here to clean a 30 ft boat and it takes a man all day long to do it...is it possable that your cleaners are not scraping the whole boat?when they cleaned mine it had been cleaned before and they only cleaned to the keel.and last year when i got the boat a man went down and found the keel was not touched and brought back up huge pieces of baracle and oysters that were in balls of 8 inches and even my water line came up when he was done at the end of the day..I was very happy..who is doing it for a 1$ a ft? Wes
Not the same
The original post was from someone with a boat in fresh water, not salt. There are no barnacles in fresh water, only slime and the occasional zebra mussel, which only seem to attach themselves to the metal parts. In my dive gear, I could do the bottom on my 32 footer in about 30 minutes using a hand scrub brush or the like.
The original post was from someone with a boat in fresh water, not salt. There are no barnacles in fresh water, only slime and the occasional zebra mussel, which only seem to attach themselves to the metal parts. In my dive gear, I could do the bottom on my 32 footer in about 30 minutes using a hand scrub brush or the like.
Raymarine Speed Impeller
I have a Raymarine Knot meter. I pull the impeller and clean it every month or so. Just unscrew the top ring and the speed impeller asymbly will lift out. There is an internal flap that will close off most of the water flow. The water flow is slowed greatly( not that it is overwhelming at any rate). I take a tooth brush and clean the impeller. Whole job takes maybe a few minutes....Definitely worth the effort.
I have a Raymarine Knot meter. I pull the impeller and clean it every month or so. Just unscrew the top ring and the speed impeller asymbly will lift out. There is an internal flap that will close off most of the water flow. The water flow is slowed greatly( not that it is overwhelming at any rate). I take a tooth brush and clean the impeller. Whole job takes maybe a few minutes....Definitely worth the effort.
Tim? what do you think
about a hundred dollars did i pay to much?because i will have it done again in a year or so..they did not use dive gear just fins snorkle and mask and they had a tool with a rope straped to his arm.but i notice he stayed down for 30 to 45 seconds at a time and took one gasp of air and was down again..would it cost more for a person in dive gear?i didnt mind paying but not sure i would want to pay more.Wes
about a hundred dollars did i pay to much?because i will have it done again in a year or so..they did not use dive gear just fins snorkle and mask and they had a tool with a rope straped to his arm.but i notice he stayed down for 30 to 45 seconds at a time and took one gasp of air and was down again..would it cost more for a person in dive gear?i didnt mind paying but not sure i would want to pay more.Wes
Seems a bit hokey
I would have a hard time charging someone for something they can do themselves, i.e., snorkel and holding your breath! I've done my own boat both ways, and you CANNOT do as good a job snorkeling as in dive gear. Its hard labor to scrape, and trying to do it while holding your breath makes for a "hurried" job. When in dive gear, you obviously have time to concentrate on the bad spots and make sure you're not missing anything. Is $100 too much? It really depends on what the job is worth to each individual. If you don't like going in the water under the boat, or are limited physically by your swimming skills etc., then its worth more I guess. I will offer this, I do not have experience in salt water cleaning boats, so I'm not sure what's fair. I know the guy I race with pays $2/ft to have his Tripp 40 cleaned every two weeks, and its docked in fresh water where there's about a 1-2 knot current running stern to bow. And the boat also draws 8 feet with a Baltoplate bottom. But then these guys are serious about winning races (and we do)! Cheers! Tim
I would have a hard time charging someone for something they can do themselves, i.e., snorkel and holding your breath! I've done my own boat both ways, and you CANNOT do as good a job snorkeling as in dive gear. Its hard labor to scrape, and trying to do it while holding your breath makes for a "hurried" job. When in dive gear, you obviously have time to concentrate on the bad spots and make sure you're not missing anything. Is $100 too much? It really depends on what the job is worth to each individual. If you don't like going in the water under the boat, or are limited physically by your swimming skills etc., then its worth more I guess. I will offer this, I do not have experience in salt water cleaning boats, so I'm not sure what's fair. I know the guy I race with pays $2/ft to have his Tripp 40 cleaned every two weeks, and its docked in fresh water where there's about a 1-2 knot current running stern to bow. And the boat also draws 8 feet with a Baltoplate bottom. But then these guys are serious about winning races (and we do)! Cheers! Tim
- Status