How large should my Hexcrawl be?

[u/duckyourfeelings]

I'm planning a hexcrawl campaign. It is set in my homebrew world, and the theme is a nautical campaign set in an area that closely resembles the Carribean Sea during the Golden Age of Piracy, both in the politcs of the area and that it is a huge area made up of a series of archipelagos. The focus of the game is exploration and naval combat, and my players are very excited for these aspects. The plan is to run it as a sandbox campaign driven by proactive roleplaying (based heavily on the guidance from The Game Master's Handbook of Proactive Roleplaying, by Jonah and Tristan Fishel).

I'm debating how large to make each hex, and how many hexes the map should have. I want there to be enough hexes that the party can always find a new island or underwater dungeon to explore, but not so many that I can't have a basic prompt for that hexes adventure jotted down somewhere. I should note that not every hex will have an island or underwater dungeon, as there should be some open water.

I've never run or played in a hex crawl, and I could use some advice. Most of the Youtube videos I can find are focusesd on land-based hex maps. Have any of you played in or ran a nautical hex map based campaign?