Its useful forever. It has 5 charges on it but you recharge it with fishoil that is made by a a cook (8 fishsteaks 1 flour). Its from as high fisher quest as the 120 fishing PS but harder to get. You use it by doubleclicking it and it tells the coordinates at sea where you can summon Charybdis, the latest HS boss .You need a group, ship or ships and a Charybdis bait, also from the fishing quests. Not many has fought the boss so far ,it has been so hard to get the oracle, ppl have forgotten about this monster if they arnt fanatic fishers I guess. My guld did our first one 8 days ago and will go again. Loot is some unique armourpart and fish stuff..what we know so far. Its more for the adventure we worked so hard to make it possible. There is a short movie fron such fight on another shard on Professions forum, Treasure hunter. Was going to lower the price a bit as it seems so unknown ..if its still there...but that account is blocked this morning..thought I had managed the account merging thing but seems not.