| FAD |
First Aid for Divers |
| Fahrenheit |
A unit of measure for temperature. Fahrenheit (1.8 * C) + 32 or 9/5C +32) |
| Fair |
A term used in shipping forecasts to describe nothing significant, no rain or showers. |
| Fathom |
A unit of measurement for water depth. One fathom equals six feet. 1 fathom = 6 feet = 1.8288 metres. Always take care on nautical charts as depths may be given in fathoms or metres. |
| Fender |
A protective object hung over the side between boat and pier, or another vessel. |
| First Stage |
The part of the regulator that connects to the cylinder. It acts as pressure reducing valve that reduces the cylinder pressure (typically 232 Bar) to about 10 Bar. This is connected to a hose to the demand valve or second stage. |
| Flaking |
laying out line on deck in parallel rows so the line will run free without tangling. |
| Flood Tide |
A rising tide. The opposite is an ebb tide. |
| Flotsam |
Goods lost from a ship which has sunk or otherwise perished which are recoverable by reason of their remaining afloat. |
| Fluke |
Flattened end of an anchor arm that bites into the ocean floor. |
| Free Diving |
Also known as breath hold diving, this is a method of diving where a diver simply holds her breath and submerges, using little or no equipment. |
| Front |
A Front is a boundary between two air masses of different characteristics. Many shipping bulletins may simply called a front a trough. |
| FSW |
Depth measured in feet of sea water. |
| Full Face Mask |
A diving system with the regulator built into a diving mask that completely covers the face, nose and mouth. Provides extra safety margin with high PO2 exposures (helps prevent drowning in case of a seizure) and is easily adaptable to communication units. |
