Edited: Many thanks for the help

[kmacdonald]

I re-read the initial post. It can't be the damper plate because it makes the noise with the engine off and the prop free-wheeling.
A cracked shaft might cause it but I think the other suggestions are probably correct. Cold water can affect different metals differently. Some become brittle in the cold. Ships built for cold waters use different steel.
Could be an issue with the gear.

[tomcolter]

I had sim prob with bad cluk cluk from shaft. A recently installed cut less worked it's way up the shaft causing shaft/strut contact. Set screw was not tightened at install. I wish you good luck

[kmacdonald]

Any word from Dockhead?

[Seaworthy Lass]

Originally Posted by kmacdonald

Any word from Dockhead?

I have not heard what the definitive diagnosis is, only that he has not turned back and that all the suggestions have been appreciated.

SWL

[Kenomac]

Originally Posted by a64pilot

If they are not proficient diving, Id advise against it, especially in open water.
first in cold water there is a natural gasp reflex that has drowned many a person, and then under a boat in even seemingly begin conditions the motion of the boat can be dangerous.
thirdly, even in shallow water, you need to be able to inflate your dry suit just a little late to prevent the squeeze it's going to do, then if you haven't Dove in it, you don't have the amount of weight to become closer to neutral, and that means a lot of experimenting in cold, open water.

If it's a rope cutter, best to leave sleeping dogs lie.

Originally Posted by a64pilot

Oh, and another thing I Just remembered, cause I don't not dive in ice.
There are special regulators required for cold water diving and or some better regs can have a cold water kit installed, apparently without the special bits, a reg can freeze up and stop working, and an inexperienced, or experienced for that that matter diver does not need that

The water temperature around Iceland is 10 degrees C this time of year which is the same temp water I was in earlier today here in Maine wearing a 7mm wetsuit.

It was no big deal; the wetsuit can easily go down to 5 degrees without an issue... I was never cold and the hookah system worked fine for over an hour. Everyone should be able to dive under the boat if the need arises IMO.

[NYSail]

Originally Posted by Kenomac

The water temperature around Iceland is 10 degrees C this time of year which is the same temp water I was in earlier today here in Maine wearing a 7mm wetsuit.

It was no big deal; the wetsuit can easily go down to 5 degrees without an issue... I was never cold and the hookah system worked fine for over an hour. Everyone should be able to dive under the boat if the need arises IMO.

Agree..... am purchasing for wife and I. 7mm full body? And hookah system is what.... tank up top with long air hose?

Thanks
Greg

[El Pinguino]

A bit cooler over on the Greenland shore ... Tasiilaq is currently 6.7*C

https://www.seatemperature.org/europ...d/tasiilaq.htm

and Scoresby Sound being a little further north is probably cooler again.... maybe 5-ish

[Kenomac]

Originally Posted by El Pinguino

A bit cooler over on the Greenland shore ... Tasiilaq is currently 6.7*C

https://www.seatemperature.org/europ...d/tasiilaq.htm

and Scoresby Sound being a little further north is probably cooler again.... maybe 5-ish

Dockhead is experiencing the problem in Iceland where the water temp is 10 degrees, not in Greenland where the water temp is 6.7 degrees. But either way, a 7mm wetsuit should be good enough to go under for a short time and have a look. With a hood, gloves and booties, I could only feel cold water when the regulator came out of my mouth. Otherwise, no difference from scuba diving in the Mediterranean except for the low visibility of 3ft here in Maine.

I used a lighter set of gloves. The hookah system is a HookaMax 100ft hose and regulator with Parker hydraulic connectors powered today by a Porter Cable oil less compressor. We also have a Thomas professional grade compressor aboard per recommendation of CF member fastbottoms.

The prop was fine as was the anode. Then I spent 30 minutes or so cleaning part of the bottom and checking all the through hull water inlets.

[Kenomac]

We’re presently in Maine bound for Newfoundland.... I’ve just offered up what works for us under the same set of circumstances. Hopefully, this can be of some help to Dockhead and his friends since he’s reported to have dive gear aboard his boat.

[LakeSuperior]

Pour water that is as hot as you can stand into the wetsuit neck, front and back, and in the booties and gloves before entering the water. It minimizes the shock and buys one an extra 10 minutes in the water.

I just returned yesterday from a week of diving in 5 deg C water. Two dives per day with a 30 minute or better duration for 7 days. Of course I am having trouble recalling why we were diving. Anyway, it's amazing how your body acclimates to the cold water after one or two dives.

[Jerry Woodward]

What about trying to run the prop in reverse for a short period? If there is something on the prop, running in reverse with forward motion of the boat may just unwind it. If not, the noise may be different possibly providing a clue as to its origin?

[Seaworthy Lass]

Dockhead has asked me to post this:

"Thanks very much for all the good suggestions, which really helped a lot. I understood after all that that it is definitely the rope cutter, as it can't be the shaft seal and it can't be the cutless bearing (shaft runs smooth and sweet). I tested this theory by comparing the sound at different power settings and I realized that it only makes a sound at low power settings -- which means that I simply set the static blade too far back from the v-notch thing. So now we're just running the engine a little harder and everything seems fine. We are now above 70N inside Scorseby Sund dodging icebergs, having a fantastic cruise, the most interesting by far of my whole sailing life. I'll post about it when I'm back in civilization. Thanks again to everyone, and especially to SWL for passing these comments back and forth."


It sounds like he is having an exhilarating adventure!

SWL

[Wotname]

^^ thanks for the update - good news indeed!