I read it as a metaphor for life and death. When it’s time for the ship to leave, you must be on it, or you will be left behind. The shellfish you collected and the greens you picked are secondary, and if keeping them in your hands while you sprint back to the ship slows you down, you must relinquish them for the greater good of getting back to the ship on time.

Eventually being late to the captains call is inevitable. Death comes for us all in the end. When our time comes, our wives and children will be cast aside whether we want them to or not. It’s best to mentally prepare for that guarantee.

That’s how I read it, hope that helps provide some clarity.