The British Museum of Natural History gave each yacht entered in the 1968 trans-atlantic race a log book asking each crew to record sightings of mammals including where,when, and under what conditions the sightings occurred. There were many sightings, I had forgotten until now, I described the porpoise in the photo, Geroge Moffett, the owner of the boat turned the log in at the end of the race. About a year later he wrote to me that the porpoise had been identified as a unique species within the family of Phocoenidae and that the Museum had attributed it the name “Guinevereous Liraki”
I have no substantiation of the story as I have long ago lost the letter.