Classic Do we know if there is a specific timer on supply drops in Nazjatar now?

Looking to pick up 3 more of these things and I dont know if its random when they spawn or not. I see people often asking in chat when the last time a supply has dropped which made me wonder if there was a specific time after it has dropped for it to drop again. Does anyone know? via /r/wow https://ift.tt/2VQ1l0z