Running total — crew of 5: 66 fish aboard vs 40 on shore (net +26 fish) 2015 108 50 −5−10 Fish per day Optimal crew: 5 — the 5th adds exactly 8; the break-even member boards Marginal product on the boat Marginal product on shore 12 34 56 78 Crew size Crew of 5: the 5th adds exactly 8 fish, the same as on shore. Marginal catch aboard equals marginal catch on shore — the optimal crew. The break-even member boards.

Drag the gold crew-size handle (or focus it and use the arrow keys). Watch where the boat stops beating the shore.