Old Mak decided to sacrifice his life.
After thinking hard, after suffering the constant mental blows of guilt, after watching the numerous deaths, Old Mak decided that the best way to atone for his sins was to sacrifice his life for the other sharks to escape.
Someone had to stand to the challenge one way or the other. If no one stood, there was a high chance that none of them would escape alive.
The pressure that was induced by the enemies' pursuit was what stimulated Old Mak to make this decision that had far-reaching consequences.
When he was younger, he already cowered once which led to his lifetime guilt that kept on haunting him for decades. At this moment, Old Mak refused to make the same mistake that was capable of haunting him forever.
He was already an old Great White Shark; he was content with dying if doing so could allow the young Great White Sharks to blossom and prosper.
"When you love something, you protect it!"
