A small ship - Rather a “boat.” There were properly speaking, no “ships” on the Sea of Tiberias. This was probably a small boat that belonged to the disciples, in which he could draw off from the shore, and teach the people without being pressed by them.
Lest they should throng him - They pressed upon him in great numbers. He had healed many, and those who were still diseased pressed or crowded on him, so that his labors were interrupted and embarrassed. He therefore withdrew from the multitude, and sought a situation where he might address them to greater advantage.