This has a lot of thematic ideas and I especially love your map. The overall layout is simple but makes it easy to read. That said, the text layout with the indentations isn't bad, but there is probably a better way to use the space available while still allowing for visual hierarchy. Try bullet points or callout boxes like you used for the encounter table. I also like the visual design, but it doesn't do much to sell the vibes: it's just "ocean" themed instead of "scary shipwreck in the ocean" themed. I appreciate the page references to the PSG. Overall a fun read and something I could see myself running.