The very words Astro navigation are often enough to send a cold shudder through even the most experienced boater. The funny thing is that although a lot of Astro jargon has an almost mystical ring about it, most of us know the "secrets" on which the whole science of Astro navigation is based. RYA Astro Navigation Handbook is ideal for anyone new to celestial navigation, or wanting to update their Astro skills. It is not a textbook or manual - it is simply a book to enable you to "just get on and do it". It is the course book for anyone taking an RYA Yachtmaster Ocean Theory Course.