Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 26-01-2016, 09:01   #1
Registered User

Join Date: Dec 2011
Location: Portsmouth NH
Boat: Gulfstar 44 CC
Posts: 30
Mooring block size

I realize a lot has to be considered with tides and current but is there a formula that relates to mooring block size (weight) and boat displacement.
My Gulfstar is 26k displacement, should I worry about a 2-3k lbs. piece of granite ?
Windwalker44 is offline   Reply With Quote
Old 26-01-2016, 09:35   #2
Registered User

Join Date: Apr 2013
Location: Penobscot Bay, Maine
Boat: Tayana 47
Posts: 2,124
Re: Mooring block size

Quote:
Originally Posted by Windwalker44 View Post
I realize a lot has to be considered with tides and current but is there a formula that relates to mooring block size (weight) and boat displacement.
My Gulfstar is 26k displacement, should I worry about a 2-3k lbs. piece of granite ?
If that's the rock you currently have, it would take quite a stiff breeze for your boat to drag it, especially if it's located in a fairly protected harbor and is fairly flat in shape (large surface area) and sunk into the mud as opposed to sitting on top of a gravel or rocky bottom so there's no big rush to get rid of it. I don't know what the official guidance is but I told my mooring guy I wanted one size up from what he'd normally recommend for my boat in our harbor, and as a result I have a 5000# rock in a pretty protected location on a muddy bottom, and my boats displacement is about 23k, but I've always considered a big rock and heavier than recommended mooring chain and pennant to be cheap insurance. It's only a couple of hundred dollars more to upgrade by 1000# or so and granite doesn't wear out so it will last about forever if the staple is also sized large. If I were in your shoes, and owned a mooring like you mention, no big hurry, but I'd try to sell it to someone with a smaller boat, and when you eventually do, have a bigger stone put down there. Or, whoever takes care of moorings in your harbor may take your 2-3k rock in trade for a bigger one, especially if he knows someone who will want to buy it from him this spring. You may never need it but if you do...
jtsailjt is offline   Reply With Quote
Old 26-01-2016, 12:51   #3
Registered User
 
Hydra's Avatar

Join Date: May 2009
Location: Lorient, Brittany, France
Boat: Gib'Sea 302, 30' - Hydra
Posts: 1,245
Re: Mooring block size

In my area, the administration in charge of moorings recommended a concrete block half the boat displacement (hard gravel bottom in the area). I had 1800kg for a 3.5 t boat.

Alain
Hydra is offline   Reply With Quote
Old 26-01-2016, 14:23   #4
Registered User
 
Blue Stocking's Avatar

Join Date: Dec 2008
Location: St. Georges, Bda
Boat: Rhodes Reliant 41ft
Posts: 4,131
Re: Mooring block size

It comes down, weight-wise, to the specific density of the object. Water being the standard 1, the efficiency of all other material will relate to this. Concrete, for instance, loses 20 -30% efficiency when submerged.
__________________
so many projects--so little time !!
Blue Stocking is offline   Reply With Quote
Reply

Tags
mooring, size

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Fused Terminal Block similar to Blue Sea Systems ST Blade Fuse Block zboss Electrical: Batteries, Generators & Solar 4 21-08-2013 21:31
6 day itinerary in BVI with kids mooring to mooring askdad Sailor Logs & Cruising Plans 1 16-03-2013 04:11
Block size main sheet 39' cruiser Swaler Deck hardware: Rigging, Sails & Hoisting 2 11-02-2013 21:42
Mooring Buoy Holding-Block Weight ? Mark Cammiade Anchoring & Mooring 16 23-08-2011 03:40
Electrified Mooring Field? Mooring Power Mule Electrical: Batteries, Generators & Solar 31 08-04-2010 08:00

Advertise Here


All times are GMT -7. The time now is 13:06.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.