I have a couple of thoughts.
POH on an Island
There could be a new house portal. Players would need to sail to the island in order to unlock access to the portal. Neighboring islands could have destination resources or monsters, and you could navigate among the islands by way of sea canoes or small boats.
Scurvy
A brilliant Briton discovered limes provide the Vitamin C necessary to prevent this disease. Players could learn a bit of naval history, if not necessarily nutrition, from a small quest on the topic.
There could be a new island, rich in fruit tree patches, where lemon (or lime if you feel inclined to create them) trees are far less prone to disease.
Limes kept in the ship's storage could deplete automatically, preventing the sailors onboard from developing scurvy on extended deployments. A cure potion or balm would have the same effect, but at perhaps a higher gp cost.
Barbarian Sailing
If wind is to be a factor in Sailing, then it would be worth the time to note that Vikings were capable of sailing against the wind.
Vikings were also kings of the river. A barbarian sailing technique could open the potential to sail the rivers of Gielinor.
10-Sep-2015 22:19:56