Propeller installation under water

Jellis

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Feb 21, 2013
5
Hunter Legend 35.5 Lake Texoma, Pottsboro, Tx
About 15 minutes after apparently proper propulsion, I lost all propulsion from my Yanmar engine on my Hunter 35.5. After my being towed in, a diver reported that the blades on my propeller had been "sheared off". Of course, the engine would run properly and the drive shaft turn properly, but there was no propulsion in forward gear or reverse. I ordered a new prop, of the size and description that was original equipment on the boat. Can a diver remove the old prop and install the new one, as well as an appropriate zinc, without hauling the boat out? Has anyone had any similar experience?
 
Sep 15, 2009
6,243
S2 9.2a Fairhope Al
this can be done if you are in shallow water where the diver can stand ...also it would be good if the water was reasonably clear ...but he might have a problem pulling the old hub off the shaft ........it may be best to short haul (leave the boat in the slings) the boat and change it that way
 
Oct 29, 2005
2,362
Hunter Marine 326 303 Singapore
With the right tools, clear vis, no wake/wave it can be done with hooka or air tank provided the prop hub don't get seized to shaft. Been there done prop change underwater couple of times.
There's always a constant fear of dropping tools and parts into Davy Jone's locker. ;)
 
Dec 19, 2006
5,818
Hunter 36 Punta Gorda
Prop

When I changed my prop in 08 on my 07 H-36 on the hard after trying to
remove the prop many hours later I had the Marina use a special tool and they
removed it very easy and so the proper tool does makes a difference.
Nick
 
Feb 6, 1998
11,701
Canadian Sailcraft 36T Casco Bay, ME
About 15 minutes after apparently proper propulsion, I lost all propulsion from my Yanmar engine on my Hunter 35.5. After my being towed in, a diver reported that the blades on my propeller had been "sheared off". Of course, the engine would run properly and the drive shaft turn properly, but there was no propulsion in forward gear or reverse. I ordered a new prop, of the size and description that was original equipment on the boat. Can a diver remove the old prop and install the new one, as well as an appropriate zinc, without hauling the boat out? Has anyone had any similar experience?
It can be done in-water but you really need to get to the root of the problem. If your blades just "sheared off" this hints at a serious corrosion issue and the strut or other below water metals could be next... A haul out would likely be a wise move to assess the rest of the underwater metals...
 
Aug 2, 2005
1,155
Pearson 33-2 & Typhoon 18 Seneca Lake
Can a diver remove the old prop and install the new one, as well as an appropriate zinc, without hauling the boat out? Has anyone had any similar experience?
Tough Call.....What you (1) can do, (2) should do, (3) must do, or (4) find best to do might be four different actions. Personally, the short haul choice sounds best. Of course, that is assuming that a haul out facility is close and agreeable to your request at a price you can be comfortable with. If you are hauled at the end of the work day you would have many hours to accomplish the project until the following morning. That would also give you the opportunity to inspect the other boat parts/surfaces in that area to check whether the prop failure caused any other damage. Galvanic changes to shaft and strut? (Because the prop fell apart for some reason) Dings on the hull or rudder? Condition of zinc?

Also, if you are allowed to work on the boat yourself or need to have the yard workers do the change must figure into the decision. Would a diver be allowed to work in the water of the marina or dock area where the boat is located? Best Wishes and keep us informed, please.
 
Dec 14, 2003
1,423
Hunter 34 Lake of Two Mountains, QC, Can
It can be done in-water but you really need to get to the root of the problem. If your blades just "sheared off" this hints at a serious corrosion issue and the strut or other below water metals could be next... A haul out would likely be a wise move to assess the rest of the underwater metals...
Real good advice here from MS. Several years ago on a trip south, I ran into crab trap hell north of Charleston, SC. Got the boat towed to a marina in Charleston, hired a diver who removed a pot, nets and several feet of line as well as the broken prop. I asked him to check the shaft and he assured me that it was not bent. I ran the engine in gear and could not see any wobbling. So I asked him to install the spare prop and resumed my trip. Two days later, in Beaufort, SC, I lost propulsion again. Towed to a boatyard, I hauled out to discover that while the shaft was straight, the strut was bent way out of shape, causing a severe misalignment in the tranny, eventually disintegrating it. New tranny, new shaft, new prop, new strut and new cutlass bearing later I was back in business. Lucky for me the insurance company deemed it an accident because of the earlier encounter with the crab pots and paid for the repair. Look at the pictures and you'll get the point that however good the diver is, there are things he can't see or figure out. In my case he probably thought the boat had an offsetted shaft and did not mention anything. In your case, MS assumption about corrosion is very valid and a haul-out could very well be the smartest decision you take. Good luck
 

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Jellis

.
Feb 21, 2013
5
Hunter Legend 35.5 Lake Texoma, Pottsboro, Tx
Thanks for the advice. I had a haul out scheduled before this happened and was waiting until the marina service department had hauled out those who made their reservations before I did. Then unprecedented rains came and all the marina service departments on the lake are literally under 10-15 feet of water and may be inoperative for months. Unless the job can be done by divers as the boat sits in its floating slip, I'll miss most of the summer boating season. I'll confer with some divers and see what they say they can do.
 

Rick D

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Jun 14, 2008
7,182
Hunter Legend 40.5 Shoreline Marina Long Beach CA
Given that...

...I totally agree. A diver should be able to do this and then have a full inspection when you haul. I would have missed mine if I had not had the prop pulled for service. BTW, I think Martec is the original supplier and could do a quick turn around for you. But, check with the guys here on this (HOW) site first.
http://martec-props.com/
 
May 24, 2004
7,164
CC 30 South Florida
Our diver guys do it down here regularly. They'll remove the prop, clean it, balance it, paint it and reinstall it as part of regular maintenance every 2-3 years. Last time I had it done it was $100 + $15 for replacing the zinc.
 

Gary_H

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Nov 5, 2007
469
Cal 2-25 Carolina Beach NC
I have replaced my prop under water several times, if that's all you need to do. I 've actually replaced my shaft under water, but if there might be other issues beside replacing a prop, as suggested you may want to haul out to see if there are other problems down there.