After completing the unlocking quest, your first priority should be the basic docks (Port Sarim, The Pandemonium), your starter ship (raft) and cargo hold, then aim to get the skiff at Sailing level ...

This article shows exactly how to collect all 8 medallion fragments in OSRS Sailing, what skills and gear you need, and how to combine them into the Medallion of the Deep. It even covers the hidden ...