This handbook has been specifically published as the official background reader to the RYA radar course. That makes it essential reading for anyone undertaking the course, but it is also a very good introduction to the use of yacht radar for those who are not seeking a formal qualification or endorsement. This edition was published in 2001 and is the third edition, the first appearing in 1991. It covers real-time radar displays and therefore is not heavily affected by new systems. The principles and applications are as current and applicable today as when the first edition was published, making it a durable work. The type of radar used as the example through the work is typical of yacht radar and essentially similar to the very first radar systems, where a radio transceiver sends out a signal and measures the reflection when the signal strikes an object. The result is produced as a screen display in real-time.