And he told his disciples to have a boat ready for him because of the crowd, lest they crush him, for he had healed many, so that all who had diseases pressed around him to touch him.
Very early in the gospel of Mark the public ministry of Jesus became enormous. The crowds that followed Jesus were extensive, so much so that Jesus had to take precautions against a mob mentality. Keep in mind, this was in a very rural setting, by the Sea of Galilee, and even here vast crowds of diverse people from all over, including people journeying from southern Judea and gentile areas like northern Tyre and Sidon, came to see and hear Jesus. His healing ministry pushed the crowds even bigger and with a desire to be closer to Him.
Jesus asked His disciples to have a boat ready for Him. This allowed two things to happen. First, it facilitated a way for all to see Him. We know from other gospel accounts the boat would be set just a few feet off shore and from it Jeus had a teaching platform from which everyone could see Him. It was sort of a floating pulpit. Secondly, when it came time to leave, the boat facilitated quick and easy transportation without a huge crowd following to slow things down.
As Mark tells it, this was Jesus at the heighth of His public ministry. The crowds love Him but only seem most attracted to His miracles. The disciples are still learning what it means to follow Him before He commissions them to preach the gospel and multiply His ministry. The conflict with the leaders of the Jews have been minimal, although the Pharisees are already plotting together against Him (see Mark 3:6).
These events will only continue to grow in Mark's gospel, until it all escalated in Jerusalem where Jesus was delivered over to those who hated Him. There He was mocked, beaten, rejected by those who once wanted miracles, scourged, and then crucified. Public acclaim became public shame... all to save sinners like me.