This information may change as more data is gathered. This table applies to the south entrance to Seaworld Barren difficulty. The north entrance and other difficulties are unknown to me so far.
Ensure all five of your Daily Quests are completed so you can activate your Marching Buff in "My Window" of your Tree. This should increase your traveling speed a little.
Top up your Food and Water on your ship before you sail to Seaworld. When inside Seaworld, Food feeds your ants and Water supports your ship in trade while carrying goods. Take the minimum amount of ants allowed for sailing (for me this is currently 6667 Soldiers), this way you will use less food.