If your chart indicates the depth of 3 fathoms and your vessel's draft is 3 feet, what is the depth under your keel?

To determine the depth under your keel, it’s essential to know the relationship between fathoms and feet, as well as account for the vessel's draft.

1 fathom equals 6 feet. Therefore, if the chart indicates a depth of 3 fathoms, that translates to 3 x 6 feet, which equals 18 feet of water depth.

Next, you must consider the draft of the vessel. The draft is the vertical distance between the waterline and the bottom of the hull (keel). In this case, the vessel's draft is 3 feet.

To find the depth under the keel, you subtract the vessel's draft from the water depth. So, the calculation would be as follows:

18 feet (total depth) - 3 feet (draft) = 15 feet (depth under the keel).

This reasoning confirms that the depth under your keel is 15 feet, making the answer correct.