Wind pushes you when you glide, and ocean currents push your boat. Both follow real data.
The world's six wind bands act on a gliding player. The wind never damages you, never stops a flight and never touches you on the ground. It changes your speed by up to about half, either way. A tailwind gets you there sooner and a headwind gets you there later, but a headwind can never leave you short of where you were going.
Boats are pushed by real ocean current measurements from drifter buoys. With the current, your boat's top speed rises by about half. Against it, your top speed drops by about half.
How long a crossing takes
A block is about 204 m of real ground, and a boat does about 8 blocks a second in still water. So an ocean crossing takes a few hours, not weeks.
- The Atlantic at 40 N is roughly 35,000 blocks, which is a bit over an hour.
- Japan to California is roughly 53,000 blocks, or about two hours.
Catching the right current is worth doing. It can take an hour off a crossing or add one.
Two enchantments that do nothing
Trade Winds and Seafarer in Enchanting stops one level short were meant to strengthen these systems. They are switched off. In game they are named "Trade Winds (inactive)" and "Seafarer (inactive)". Do not trade for them.