https://www.ign.com/wikis/assassins-creed-4-black-flag/White_Whale#Confirmed_White_Whale_Locations
Confirmed White Whale Locations
When the whale shows up, an icon will pop up on your map. You will be prompted to if you want to share the location or not. Once that happens, sail over to the icon on the map to begin your harpooning.
950, 547 - North east of Great Inagua
888, 130 - East of Ile a Vache
880, 427 - North of Tortuga, South of Great Inagua, East of Punta Guarico
877, 654
677, 320 - South of Cumberland Bay
674, 315 - South of Cumberland Bay
658, 831 - South east of Floridian peninsula
638, 901 - North of Abaco Island
576,115 - Between Kingston and Isla Providencia
862,310 - West North of Petite Caverne, south of Tortuga
419, 44 - West of Isla Providencia
418, 39 - South of New Bone, West of Isla Providencia
326, 263
216, 498 - West of Pinos Isle
198, 346
173, 655
167, 651