Overwintering on a mushroom anchor

[woedwards33]

Hello!


I am looking to avoid putting my Allied Mistress 39 on the hard this winter. Located in Penobscot Bay, Maine. Have an opportunity to buy a 300lb Mushroom anchor, well rigged for 20 foot depths, and considering setting it up in one of the several "Hurricane Holes" up here and leaving her on it for the whole winter. Do you think this will be sufficient in the storms to come? does anybody out there have experience in heavy weather with mushroom anchors? I honestly don't know how they compare to a big slab of granite but have been told by many I'd need at least 4000lbs of stone to be safe for a Maine winter. Thanks for any information!

[Knotical]

Few of my neighboring harbors have boats moored through the winter, most of the harbors around us use mushroom anchors.

[DougR]

Back when I was keeping a boat on a mushroom anchor, 300lb. was considered about the right size for a 30’ boat, and a 39-40 ‘ boat would use about 500 lb.
This was in NJ in the summer time...

[deblen]

https://www.offcenterharbor.com/vide...ayne-hamilton/


https://shop.hamiltonmarine.com/depa...ing-%7CMO.html

[Reeve21]

That sounds small to me.

I'd be very concerned about chafing over the course of a winter.

[Benz]

300lb is small-ish for that size boat. I have a 500# mushroom I overwintered on with a 31' boat, and a concatenation of twisting chain, tide, and ice conspired to move it into shallower water. If your chain can't shorten up by twisting (mine is is a tidal whirl--still trying to get a quieter spot), and the water won't freeze at low tide and lift everything with it, then a 500# will probably be OK.

[SailFastTri]

800# minimum. However, in Maine it’s likely to get trapped in ice and I’d be concerned about hull crush damage, through-hull fitting damage, and the whole assembly (mooring/chain/boat) being carried elsewhere by the ice sheet. Chafe is of course also a big concern.

[Kettlewell]

Do other boats ride on moorings in that hurricane hole over the winter? If it is really well protected ice is likely to be a problem. Even just a small layer of ice will slice through fiberglass and even wooden hulls eventually, and can damage moorings too if the ice sheet gets thick enough to pull on the chain. Plus, how does your boat drain? If there are any through hulls that have to be open to drain deck or cockpit water they can freeze up solid as fresh water runs into them, sometimes popping a hose off or splitting one. Even though I had a deep wooden sailboat I found that in the water in southern New England I needed to run heat inside the boat over the winter in order to prevent water lines, tanks, and cockpit drains from freezing up. Plus, a 300-pound mushroom is way too small for a 39-foot boat. Mushrooms are only good in softer mud bottoms. Won't work if the bottom is too firm or rocky. Go with whatever the locals are using.

[GordMay]

According to ‘SECURE-MOOR’ ➥ https://www.wwewirerope.com/anchors....shroom-anchors
A 300 lbs mushroom anchor may be suitable for a 30-32 ft. boat.
A 39 Ft boat would require [at least] 500 lbs.

Mushroom anchors, properly set, in suitable substrate*, may have a holding power of up to about 10 times their weight.
* Mushroom anchors work best in softer bottoms, where it creates penetration, based on suction.

[j.g.evans]

I kept a 29' boat in Raritan Bay on a 500 lb mushroom for many years. The mudroom sank in the mud all the way to the top of the shank. This took years. I had 20' of 3/4 chain and then 10' of 3/8 chain. Then I had chain to the deck cleats for chafe protection. There was more than 10 miles of fetch to the NE. This worked through many "Northeastners" summer storms.

Other boats of the same size and bigger were found on the shore with all their chain and 200-300 lb mushrooms after several storms.
You may not get bad storms in late winter and be OK. But, unless you have a much larger mushroom that has sunk over the years, I think your boat will be lucky to survive a bad storm. Isn't the Maine shore rocks?

[jen1722terry]

We moor in Northeast Harbor on Mount Desert Island. We haul the boat each fall but a few yachts do stay on the moorings. All moorings are town maintained and you rent from the harbor master.

Oddly, we've heard that this little harbor doesn't freeze, or doesent freeze much. Might be an option and is just a long day sail from Penobscot Bay.

One thing about this harbor and some others in Maine is that it is shared with the lobster fleet, which may retard ice with all the comings and goings.

Cheers

[Rightbrainer]

Do a little research and contact a local mooring service company on Penobscott Bay. They've seen it all and know what works and what doesn't. They will know every inch of the bottom in that bay. A 300# piece of cast iron rolling around on a granite bottom won't work as well as it would on a mud bottom. Local knowledge plus experience

[psk125]

Reminds me of the guy who anchored his boat in the St. Lawrence last November IIRC, expecting to head south in the spring. Ice trapped the boat, dragged it, and apparently froze his bilge pump, so she sank. A good hurricane hole may be calm enough to freeze over. How do you get to a boat that's trapped in ice too thick to chop through in a skiff and too thin to walk on?

[GordMay]

Originally Posted by psk125

Reminds me of the guy who anchored his boat in the St. Lawrence last November IIRC, expecting to head south in the spring. Ice trapped the boat, dragged it, and apparently froze his bilge pump, so she sank. A good hurricane hole may be calm enough to freeze over. How do you get to a boat that's trapped in ice too thick to chop through in a skiff and too thin to walk on?

You may be thinking of the “Not A Starship", which sank, in the lower St. John River, this spring.
See:
“Saga of the Sunken Sailboat - from Start to Sunk” ➥ https://www.cruisersforum.com/forums...nk-285261.html