Bill Johnson at Aztec Sailing has created this superb on-line learning resource with a significant quantity of useful material for trainee crew and skippers on sea going yachts.
It is also a useful reference site for experienced skippers and other people who need to understand the sea and maybe do a little revision.
It covers the theory for 'day skipper' through to 'yacht master ocean'. It gives the basics in very clear language and builds in the detail in a steady progression so it is refreshingly easy to learn.
If you find this useful please make use of the web site's honesty box. I think you will agree its well worth supporting.