The Lost Treasure of Blacktide

Legend has it the feared BLACKTIDE crew went missing and hid a load of treasure somewhere. All that was left behind was this message. Decode the message using the key below to uncover your first clue. 

ᛞᛖᚨᛞ ᛗᛖᚾ ᛏᛖᛚᛚ ᚾᛟ ᛏᚨᛚᛖᛊ