Mooring Chain and Shackle Sizes?

[savageseadog]

What rule of thumb sizes would one need for a 6 Tonne boat (sailing yacht) in non tidal (currents) but exposed to wind conditions and a less exposed very strong tidal area? A full range of sizes would be good if it helps others

 

[philip_stevens]

This link will show you the Truro Harbour recommendations, though it only shows boat length and not weight.

 

[vyv_cox]

This link will show you the Truro Harbour recommendations, though it only shows boat length and not weight.

Those chain figures are very similar to the ones used on Menai Strait. Two anchors are used instead of blocks in these very strong tidal waters, one each upstream and downstream. My original boat was 27 ft, for which the mooring I used had a pair of 1" ground chains and 3/4" riser. Subsequently I went to a 29 ft boat, then a 34 ft one. The chains were deemed suitable for each change. The buoy may have been bigger to cope with the depth of water. Mine was in 11 metres.

 

[KREW2]

Roughly the same weight as my boat. I have an 18ml riser. As 18ml chain is to heavy to bring on deck it comes through a hippo support buoy, held in place with an 18ml welded shackle. I then have a 5 meter 12ml chain bridle, they are made up with the link at one end being round and large enough to wreath the 12ml bridle back on itself through the 18ml welded shackle. Onced wreathed a pickup buoy on 7meters of rope is shackled and moused onto the other end.