If the chart indicated 6 fathoms and your draft is 3.5 feet, what is the actual depth of water under your keel?

To determine the actual depth of water under the keel, it is crucial to convert the charted depth from fathoms to feet, as it is specified in feet for the draft of the vessel. One fathom is equivalent to 6 feet. Therefore, if the chart indicates 6 fathoms, this equates to:

6 fathoms x 6 feet/fathom = 36 feet.

Next, to find the actual depth of water under the keel, you need to subtract the vessel's draft from this depth. The draft of the vessel is provided as 3.5 feet. Thus, the calculation would be:

36 feet (chart depth) - 3.5 feet (draft) = 32.5 feet.

This result indicates that there are 32.5 feet of water beneath the keel, making it the correct answer. Understanding conversions between measurement units and performing the subtraction are key components in navigational calculations, which ensures safe passage and proper depth awareness while operating a vessel.