In Ecclesiastical imagery and symbol, the ship is the picture of the pilgrim church on earth. The best ship example would be the Irish coracle, in which monks set out, letting the wind take them and wherever they landed, they spoke to the people about Jesus.
The church was never intended to be static, but to move according to the wind of the Holy Spirit. The church is founded on the sure foundations of Father, Son and Holy Spirit, revealed in scripture. However, each generation seeks to be authentic to those foundations in the circumstances it finds itself in.