## Blog Post

### Rhumb Line

*: A conventional line on the Earth’s surface that intersects all geographic meridians at the same angle. It has the shape of a spiral that approaches the poles without going through them. (more…)*

**The Rhumb Line**### Nautical Charts. Types of Scales.

* The Nautical Charts* showing the Earth’s surface or a portion thereof on a plan, in a certain proportion (scale) and with deformations subject to mathematical laws. (more…)

### Echo Sounder. The correction of depth.

* Echo Sounder*: It is an electric device used to determine the water depths by measuring the time interval for sound waves to go to the sea bottom and back again. It is also called Depth Finder or Acoustic Depth Finder. (more…)

### Estimated Time of Arrival. ETA

* ETA*: Conventional abbreviation for ‘Estimated time of arrival’ or ‘Expected time of arrival’. The estimated time of arrival or ETA is a measure of when a vessel is expected to arrive at a certain place. (more…)

### The relationship between distance, speed and time.

The relationship between distance, speed and time is based on the well-known formula:

Distance = Speed * Time (more…)