Comparing the church to a fishing vessel is by no means new, Jesus himself calling Peter and Andrew from their trade as fishermen said to them "Follow Me, and I will make you fishers of men."

The world is the sea, the church is the boat, the Christians are the crew, the lost are the fish, and the gospel is the means by which they are caught and drawn up into the boat. That analogy is intensely useful, it teaches us for instance that the main calling of the church is to be about the business of “Man-Fishing” and spreading the gospel rather than simply taking the crew on pleasure cruises.

As a fisherman, Peter knew well how difficult and punishing fishing was. He’d had the terrifying experience of going through the sudden violent storms on the Sea of Galilee in an open boat. He’d had many a night of backbreaking toil without catching anything. As an aside I’ve often wondered if that wasn’t why Jesus picked fishermen to be his disciples, they after all knew what it was to persevere and suffer hardship to land a catch.