From "Live With The Whale" written by a dietary researcher, Jun Akamine. These "whale men" (whaling industry workers) Akamine interviewed had dissected the whale for half a century. When they put a kitchen knife into the body, they can instantly find whether it is a harpoon or the bone. And if they hit the bone, the cutting edge stops just before it hits like "Sundome in Karate". They say that it will take five or ten years to acquire the skill to let a kitchen knife cut quickly without putting extra force.
"March 9 2019
from “Oriori no Kotoba” by Kiyokazu Washida, The Asahi Shimbun"