Reminds me of Tom Neale's "An Island to Oneself" - https://harpercollins.com.au/products/9781775492979

An amazing book - well worth a read - I found a first edition years ago, and hadn't expected it to become quite so valuable.

Luckily you can read the entire book on his daughters site, or at least you could in the past.

Unrelated but similarly enjoyable is: Shrimpy: A Record Round-the-World Voyage - https://en.wikipedia.org/wiki/Shane_Acton