1999 Oceanis 352 - two projects I want to tackle between now and May 1st.

[GFS]

The first is to replace the 18 x 12 fixed three blade propeller. The boat currently cannot achieve the propeller matching speed of 3,550 to 3,700 rpm, it labors around 3,200 rpm and the boats stern is driven down flooding the lower portion of the swim platform below the water line. Planing never occurs. I am thinking about installing a tuned MAX-PROP three blade which should solve the power issue, provide feathering and give better control in reverse. The question is has anyone else experienced the boat sitting down under power and did changing the prop improve the situation.

The second is to replace the ground tackle. The boat came with a Lofran's manual windlass, a 25 lb Mantus anchor with 10' of chain and 100' of nylon 3 strand. I am planning to upgrade to Lemar Pro 1000 electric windlass, a 35 lbs Mantus anchor with 250' of 5/16 HT chain and 50' of nylon 3 strand. My question is does the ground tackle seem reasonable for a 35' boat and for those 352 owners; will the 300' of rode fit nicely in the chain locker?

I welcome all comments.

 

[Ralph Johnstone]

it labors around 3,200 rpm and the boats stern is driven down flooding the lower portion of the swim platform below the water line

This phenomenon is called "squat". It's what happens to a displacement hull as the speed increases. You're only solution is to go slower.

Planing never occurs.

It's a displacement hull. It can't plane.

I am thinking about installing a tuned MAX-PROP three blade which should solve the power issue, provide feathering and give better control in reverse.

If the prop is smaller or has less pitch, it'll solve the power problem. You should purchase the $$$ prop only if it satisfies a particular need.

Mantus anchor with 250' of 5/16 HT chain and 50' of nylon 3 strand.

Any chance you've written the chain and nylon rode backwards ? ? ? Maybe 250' of nylon and 50 ft. of chain ?

Sorry if this complicates your plans .................... just stating the cold hard facts.

 

[jssailem]

Good morning GFS and Welcome to the SBO forum.

Prop and anchor questions are popular discussions here on SBO. I suspect you can do a search for either and discover a wealth of responses for all sizes and brands of boats.

When you think about these universal subjects, the brand of the boat is a lot less important. The physics and expectations of the boat owner are more the critical issue.

PROP
You are on the right path based upon your description of what happens when you power up your boat (the stern goes beneath the waves). It sounds like the prop is not pitched correctly for your boat/engine/transmission. I had the same experience with my old prop.
Old prop New prop


Huge difference in performance. No stern submersion, powered performance with less drag.

Your investment in a properly tuned Max Prop will yield improvements in Sailing and Auxiliary power performance.

ANCHOR
I like the Mantus. I have a 35lb Mantus anchor on my 35ft boat. I have 100ft of chain and 250ft of nylon rode. I do not plan on anchoring in coral strewn waters at 50ft depths. (5to1 scope - all chain). Knowing your anchoring depths can save you a lot of weight being carried in the bow. A foot of nylon rode is easier to store than a foot of anchor chain.

I would encourage your looking at the many anchor posts here on the website. You will find answers to questions on this subject you have not even begun to consider.

Again welcome.

 

[SycloneDriver]

You might want use an optical tach to check factory tach. I wouldn't replace a prop based only on the factory tach. Will the motor rev much past 3200 rpm in neutral?

The boat is probably squatting because it is trying to plane, it never will. What is the speed through the water at 3200 rpm?

Is the prop clean? My prop was terrible, cleaning it didn't seem to make much difference though.

 

[Mechone]

The first is to replace the 18 x 12 fixed three blade propeller. The boat currently cannot achieve the propeller matching speed of 3,550 to 3,700 rpm, it labors around 3,200 rpm and the boats stern is driven down flooding the lower portion of the swim platform below the water line. Planing never occurs. I am thinking about installing a tuned MAX-PROP three blade which should solve the power issue, provide feathering and give better control in reverse. The question is has anyone else experienced the boat sitting down under power and did changing the prop improve the situation.

The second is to replace the ground tackle. The boat came with a Lofran's manual windlass, a 25 lb Mantus anchor with 10' of chain and 100' of nylon 3 strand. I am planning to upgrade to Lemar Pro 1000 electric windlass, a 35 lbs Mantus anchor with 250' of 5/16 HT chain and 50' of nylon 3 strand. My question is does the ground tackle seem reasonable for a 35' boat and for those 352 owners; will the 300' of rode fit nicely in the chain locker?

I welcome all comments.

What??? First off the max rpm of your engine is more than likely 3600 RPM , 2nd you should never go more than 80 % of rated RPM about 2800. The hull speed of that boat is 7 knots ,I have the same boat and get 7 knots on flat water @2800 RPM with a Kiwi prop, however I cruise at about 2400 RPM doing over 6 knots. 3rd the 351/352 which is the same boat had a design issue of the keel being too far back ,thus the stern sitting in the water, you can help it by moving weight forward ( more chain at least 100 feet a bigger anchor and keeping the forward water tank under V birth full . And finally you can get 10 x the info on your boat by joining the 351/352 facebook site with about 300 owners of the same boat , all manuals ,mast, parts engine manuals etc etc in the file section, along with tons of mods. And your gear box is most likely around 2:1 ratio the prop is turning 1/2 the RPM of the engine

 

[GFS]

Thanks to all for the information; gives me much to consider, I will also reach out to the 351/352 group as well.

 

[Tally Ho]

The first is to replace the 18 x 12 fixed three blade propeller. The boat currently cannot achieve the propeller matching speed of 3,550 to 3,700 rpm, it labors around 3,200 rpm and the boats stern is driven down flooding the lower portion of the swim platform below the water line. Planing never occurs. I am thinking about installing a tuned MAX-PROP three blade which should solve the power issue, provide feathering and give better control in reverse. The question is has anyone else experienced the boat sitting down under power and did changing the prop improve the situation.

The second is to replace the ground tackle. The boat came with a Lofran's manual windlass, a 25 lb Mantus anchor with 10' of chain and 100' of nylon 3 strand. I am planning to upgrade to Lemar Pro 1000 electric windlass, a 35 lbs Mantus anchor with 250' of 5/16 HT chain and 50' of nylon 3 strand. My question is does the ground tackle seem reasonable for a 35' boat and for those 352 owners; will the 300' of rode fit nicely in the chain locker?

I welcome all comments.

You won’t ever get her on a plane…unless you are surfing down a big wave…
Are you a converted power boater by chance?
The squat is normal when under power.
Your RPM issue could be a lot of things (dirty bottom, dirty prop, over pitched prop, poor engine performance, etc).

As already said, for a 35 foot boat, 250 feet of chain seems like over kill and a lot of weight to carry around.
If you are cruising the world and living aboard, maybe….but otherwise, seems like you want to reverse the ratio of chain to rope.

Greg

 

[Ralph Johnstone]

.

Are you a converted power boater by chance?

OUCH ! ! !

 

[Tally Ho]

.


OUCH ! ! !

No offense intended!

Just curious.

Greg

 

[David in Sandusky]

Your boat’s hull speed is 7.5 knots. If you watched your boat moving in flat water at 1 knot, you would see several small waves forming at the water line, and moving with the boat. As the boat increases in speed, these waves increase in length and depth, so that there are fewer waves moving with the boat. Finally, you reach a speed where there is just one wave. It has a peak at the bow, and another at the stern, while the boat is down in the trough. At this point, the boat needs a lot more power to climb the peak at the bow, go faster, and plane on the bow wave. This speed is called hull speed. None of our inboard engines have enough power to lift our sailboats up the bow wave to go faster. Reaching in a strong wind and/or a following wave sometimes provide enough power to plane our displacement hull shapes.

Meanwhile, the stern peak of the single wave at this (hull) speed is well above the normal level of the wake at lower speeds. In your case, this results in flooding of your stern scoop. On our boat, the water comes up the cockpit drains to flood a little water into the cockpit! We love it, because it means we are really moving, without looking at the gps! (Our hull speed in a shorter boat is 6.2 knots.) If your engine and prop have enough power, it may be starting to push your bow up the bow wave and make a few tenths of a knot above your hull speed of 7.5 knots. This would lift your bow and drop your stern a little more, increasing the flooding of your scoop.

In this case, another prop will not move you any faster. A prop with reduced twist will allow you to reach 3600 rpm, but will not drive you any faster. A feathering prop, with blades that turn edge on to the water will reduce drag and increase speed while sailing, especially in light winds.

If you are experiencing a flooded scoop at around 7.5 knots (through the water - a gps measures speed over ground, so tidal currents will increase or decrease your gps speed) enjoy it! All is well. Trimming the boat down at the bow with chain, or full tanks as suggested will reduce scoop flooding, while increasing the probability of waves breaking over your bow, and slowing you a little.

All the best with your boat! We have enjoyed chartering Beneteau 35’s a number of times.

 

[Mechone]

Your boat’s hull speed is 7.5 knots. If you watched your boat moving in flat water at 1 knot, you would see several small waves forming at the water line, and moving with the boat. As the boat increases in speed, these waves increase in length and depth, so that there are fewer waves moving with the boat. Finally, you reach a speed where there is just one wave. It has a peak at the bow, and another at the stern, while the boat is down in the trough. At this point, the boat needs a lot more power to climb the peak at the bow, go faster, and plane on the bow wave. This speed is called hull speed. None of our inboard engines have enough power to lift our sailboats up the bow wave to go faster. Reaching in a strong wind and/or a following wave sometimes provide enough power to plane our displacement hull shapes.

Meanwhile, the stern peak of the single wave at this (hull) speed is well above the normal level of the wake at lower speeds. In your case, this results in flooding of your stern scoop. On our boat, the water comes up the cockpit drains to flood a little water into the cockpit! We love it, because it means we are really moving, without looking at the gps! (Our hull speed in a shorter boat is 6.2 knots.) If your engine and prop have enough power, it may be starting to push your bow up the bow wave and make a few tenths of a knot above your hull speed of 7.5 knots. This would lift your bow and drop your stern a little more, increasing the flooding of your scoop.

In this case, another prop will not move you any faster. A prop with reduced twist will allow you to reach 3600 rpm, but will not drive you any faster. A feathering prop, with blades that turn edge on to the water will reduce drag and increase speed while sailing, especially in light winds.

If you are experiencing a flooded scoop at around 7.5 knots (through the water - a gps measures speed over ground, so tidal currents will increase or decrease your gps speed) enjoy it! All is well. Trimming the boat down at the bow with chain, or full tanks as suggested will reduce scoop flooding, while increasing the probability of waves breaking over your bow, and slowing you a little.

All the best with your boat! We have enjoyed chartering Beneteau 35’s a number of times.

First off the boat gets a flooded stern @ 4 knots and it is because of the placement of the keel, like I said above . Oh and adding weight to the bow of a couple hundred pounds was suggested by Ted Brewer , but hay you don't own one and know more . Like I said to the OP move on to facebook too many wrong opinions . And running any diesel above 80% of max rpm will destory it and the other 300 owners don't get it going 7.5 knots

 

[Davidasailor26]

And running any diesel above 80% of max rpm will destory it

From the Yanmar YM series manual - “The YM series engines are designed to be operated at maximum throttle (3600 rpm) for less than 5% of total engine time (30 minutes out of every 10 hours) and cruising speed (3400 rpm or less) for less than 90% of total engine time (9 hours out of every 10 hours).”

That’s one example, but I’m sure there are others, and plenty of diesel owners claim to run at full throttle for brief periods to clear any carbon build-up without any ill effects. Also, an engine designed to run at up to 3600 will not be any happier lugging around over-propped. It will just be burning its maximum possible amout of fuel at a lower RPM, putting out less power.

To the OP - do check the accuracy of the tachometer before making any permanent changes, and also check other things like condition of the exhaust elbow and boat bottom. A new prop might help with the RPM’s if everything else is in order. I would be surprised if it would help the squatting issue - The boat just knows how hard it’s being pushed, not what prop is pushing it there - but jssailem’s experience suggests maybe it could help.

For the anchor rode - 250’ of chain + 50’ of nylon would be unusual proportions. Most of the time you’ll be using just the chain, so you’ll still need a snubber, and that is a lot of weight to carry. On the good side there are some advantages of using all chain, so it’s a trade off to think about.

 

[Mechone]

Your YM wasn't made until 2004 and produces max hp @3200 RPM as per Yanmar. The OP if he even has a Yanmar is almost 25 years old many 351/352 came with Perkins M30, Volvo MD2030 and an older Yanmar model and no quicker to destory an engine running it WOT especially one that's almost 25 years old

 

[Davidasailor26]

Your YM wasn't made until 2004 and produces max hp @3200 RPM as per Yanmar. The OP if he even has a Yanmar is almost 25 years old many 351/352 came with Perkins M30, Volvo MD2030 and an older Yanmar model and no quicker to destory an engine running it WOT especially one that's almost 25 years old

For any future passers-by of the thread those are the specs for the newer 3YM30AE, first built somewhere around 2014. The original 3YM30 puts out maximum horsepower at its fuel stop speed of 3600 - https://www.maritimepropulsion.com/files/pdf/1001374

We don’t know what kind of engine the OP has, but he says it should be able to go to 3550 to 3700. If that’s the case and it’s only going 3200 max something needs to be changed or it’s just lugging the engine, generating excess heat and wear.

 

[Ralph Johnstone]

We don’t know what kind of engine the OP has, but he says it should be able to go to 3550 to 3700.

The OP has stated a few other unconventional ideas in his first post, so sitting in my armchair here, I'm going to go with your thoughts and literature.

Also, if the OP was willing to simply bend at the waist and take a close look at the engine, I'm pretty sure he'd find Yanmar's usual aluminum ID plate sitting right out in plain sight as shown for this 2GM20F.

Someone's got to say it but I'm afraid the OP is either not too experienced or not too ambitious.