Rather Strange Instincts
This is why Grayson and his diving partner made no unexpected movements when they saw the seals. It was weird that they were being approached so quickly. Particularly when one of the seals decided to get up and personal with the divers.
Sign Of Aggression
When a seal comes so near to a human so quickly and unexpectedly, it is usually interpreted as a sign of aggressiveness. Grayson and his companion, fortunately, handled the issue nicely. So good, in fact, that the seals wanted to join in on the fun.