You spawn on Starter Island with a Rowboat. It is slow. Painfully slow. Six real minutes to sail from Starter to Shell Island — a distance that takes a Caravel about 2 minutes. The Rowboat can only reach three islands. You cannot access Jungle Island, Desert Island, or any mid-to-late-game content. The Rowboat is designed to be outgrown within your first 3 hours of gameplay. Most players keep it for 15.
The Rowboat problem: every minute you spend sailing is a minute you are not earning Beli, not gaining XP, and not progressing. If you spend 40 percent of your playtime sailing with the Rowboat and 60 percent actually playing, upgrading to a Caravel (15 percent sailing, 85 percent playing) effectively increases your productive playtime by 25 percent. Over a 50-hour playthrough, that is 12.5 extra hours of actual progression — the equivalent of gaining 12.5 hours of game time for the price of a 50,000-Beli boat.
The ship progression path. Rowboat (free, starter): level 1 through roughly 25-30. Replace immediately when you can afford the Caravel. Sailboat (10,000 Beli): a trap. It is faster than the Rowboat but still cannot reach mid-game islands. You will replace it within 5 hours. Skip it entirely. Caravel (50,000 Beli): buy at roughly level 25-30. First real ship. Reaches every First Sea island. Cuts sailing time by roughly 60 percent compared to the Rowboat. This is the ship that unlocks the game. Galleon (250,000 Beli): buy at roughly level 150-200. Faster than the Caravel. Needed for chasing Pirate Raid captains and Sea Beasts efficiently. Frigate (500,000 Beli): buy at roughly level 300+. Second Sea content. Dragon Ship (1,000,000+ Beli): endgame. Fastest ship in the game. Buy when Beli is no longer a constraint.
The Sailboat trap deserves special attention because it catches so many players. You have 10,000 Beli at level 15. The Rowboat is miserable. The shop offers a Sailboat for 10,000. It is faster. It feels like an upgrade. You buy it. Two hours later, you have outgrown it — it cannot reach Desert Island or beyond. You need a Caravel. Those 10,000 Beli are gone. If you had saved them toward the Caravel, you would be 10,000 Beli closer. The Sailboat is a comfort purchase disguised as an upgrade. Skip it. Save for the Caravel.