As I add things to flesh out the Isle of the Unknown I will post a summary here along with the hex it is in. Generally I will post the descriptions, plot hooks, etc. but leave off the game statistics (unless there is a desire for game statistics?).
On the southern shore of the bay sits the town of Ilio. The town relies heavily on fishing (along with vineyards and some farming).
Over the past few weeks a strange red ooze has been filling the bay corroding the hulls of ships. Some fisherman have disappeared. The ooze can be traced to a small cave along the shore. The cave can only be entered at low tide.
Behind the ooze lies Yapesh, a wizard who, having been taunted by his peers as a scrawny boy in Ilio now seeks revenge against his persecutors. He has sworn allegiance to a terrible brine demon in exchange for his wizardly and alchemical powers. The brine demon takes the form of a giant bipedal shrimp with a blue crystalline rhombus instead of a head. The demon attacks with a powerful psychic attack that enslaves those it does not kill outright.
Yapesh's cave is full of alchemical and magical traps of his own devising, along with the carnivorous shrimp-spawn of the brine demon, psychically enslaved fisherman, a dangerous brine elemental that takes the form of an enormous, iridescent snake, and treacherous portals to a watery extra-planar domain. Beware high tide.