How To Measure Chain Size For Windlass. This then becomes the size of the chain for example 8mm, 10mm etc. If the links are the correct diameter but the length wrong, the gypsy may not catch the links to get traction.
Marking as a backup is still a good idea. Another issue is matching the gypsy on the windlass to the chain size and type. P = pitch inside link.
Often availability and the cost of the right gypsy enter the calculus of which chain size and type is right.
The boat’s specification sheet and sometimes the owner’s manual will have your boat length listed. Measure the depth of the anchor locker to determine the amount of “fall” available (distance between the top of the anchor locker and the top of the anchor rode when it is. Take a section of your chain, lay it out in a straight line, and measure the dimensions as shown below. If the links are the correct diameter but the length wrong, the gypsy may not catch the links to get traction.