Displacement, 145 tons.
Draught of water on straight keel, 5 feet 2 inches.
Length of straight keel, 60 feet, then running away in a curving line upwards, till at the bow it draws 10 inches.
Length of centre-board, 24 feet.
Total depth of ditto, 15 feet; weight, 7 tons.
Foremost end of ditto, about 8 feet abaft the foremost end of straight keel.
When let down, it descends 10 feet at the further end, and 8 feet at the foremost. It is made of oak, with sufficient lead let in to make it sink. By an ingenious mechanical contrivance one man is enabled to raise and lower it with perfect facility.
There is another centre-board abaft, about 10 feet from the stern, which is 8 feet long, with a total depth of 9 feet, and, when down, extending 5 feet below the keel.
Length over all, 113 feet.
The extreme beam is 26-1/2 feet at 40 feet from the rudder-post running aft to about 19 feet at taffrail; forward, it decreases about 20 inches when abreast of mast, thence runs away sharp to about four feet at the bow.