I started this series of Advanced Seamanship Notes to bring to light specific areas of sailing knowledge which are A. difficult to locate on-line or off, and B. provided by a Mariner who is recognizably a ’Master’ - in the true sense of the word.  Captain J H Illingworth was not only considered the ’father of offshore sailing & racing’ in postwar Britain- he was also the instigator of the Sydney to Hobart Race in Australia, in 1945.  That alone could be pedigree enough for my purposes- but add to that the fact that Illingworth was also a submarine Captain in WWII and suddenly you may realize, as I did- that what Illingworth did not know about waves and the upper layers of the ocean and their effect on a sailing boat is little more than chafe on the wind. Come take a knee, as I have, at the knee of a Master Mariner- and learn about Waves. If you would like to listen to fantastic stories of sailors in small vessels taking on the ocean in the last 150 years, all selected & read by me an actual sailor, check out the ’Mariner’s Library’. https://podcasts.apple.com/gb/podcast/the-mariners-library/id1710666955 If you would like to check out The Mariner Youtube Channel - we have gear reviews, how to videos, seamanship training videos and on the water reports. Remember to dock your finger carefully on the subscribe button! https://youtu.be/t0cfY6HqjLA Finally, to support the production of this material please consider heading over to Patreon. https://www.patreon.com/themariner Edward William Insurance. Please visit https://www.edwardwilliam.com/boat-insurance/proposal-form?pid=ORT Remember to quote the code MARINER10  to receive 10% off your premium.