Question 902Navigation General

The correct answer is C) Add the draft of the vessel. The fathometer reading provides the depth of water under the keel of the vessel. To determine the total depth of water, you need to add the draft of the vessel to the fathometer reading. This is because the draft represents the distance from the waterline to the bottom of the keel, so adding the draft to the fathometer reading gives you the total depth of water. The other options are incorrect. Subtracting the sea water correction or the draft of the vessel would give you the depth under the keel, not the total depth of water. Adding the sea water correction would also not provide the total depth.