@stump I believe sperm whales do use echolocation but that other species like the humpback do not. Maybe it is that toothed whales do and baleen whales don’t. I’m not positive though.
@marinelife Yes there is oil in the blubber and so the blubber was removed from the whales during the whaling days to harvest this oil. But, it is my understanding that the sperm whale’s head contained spermaceti in an upper compartment at the top of its head and pure oil in the lower jaw – like this. I saw centuries old implements that were used to scoop the oil out of this compartment (termed “junk”). The oil was supposedly the purest available at the time. It was my interpretation that spermaceti, harvested from the organ in the top of the head, was a wax at room temperature and when heated would melt into an oil but that this was different from the oil derived from the junk…but the internet makes it sound like it iss one and the same.
From Wikipedia, it sounds like the exact purpose of spermaceti is not known; they say it may control buoyancy and/or aid in echolocation and/or have something to do with aggression.