Beryl is blocking my trade route

I've recently discovered the new world and am trying to populate and set up production lines for rum to my main island, but O'mara's beefiest island is right on the trade route from old world to new world, so every time my trade ships pass, her harbor blows them to splinters. She's too powerful to attack and I don't have the economy to buy out the island yet. How can I divert my international route to avoid her attacks?