Why does Santiago wish Manolin was with him?

Santiago wishes he had Manolin with him to help hold the line after hooking the fish. He has to let the fish take the line it wants or risk losing it. Eventually, the fish will tire itself out and die. "But four hours later the fish was still swimming steadily out to sea, towing the skiff, and the old man was still braced solidly with the line across his back" (45).