There is trading between the continents. You can purchase a trade pack at a Cargo Seller and transport it to the opposite continent. This will reward you with some amount of Onyx Archeum Essence, which is a valuable commodity. In essence, this is a simple thing to do, but there are dangers on the way.
First of all, while on the open sea you are exposed to PvP combat. You can limit that by going on the ferry that travels between cargo trading posts and showing the cargo ship captain a Captain’s Protection item you can buy from an NPC at the trading post. This will make you immune to PvP while on the captain’s ship and should ensure your safe travel to the other continent.
However, there are ways that pirates can snag you off a ship if you’re not careful. I suggest that while in transit you have your character grab onto something like a ladder and hold it until you have reached your destination.