Water carries sound and it amplifies it. The crowds were so crushing that in order to even have space, Jesus launched into one of the sailboats (not a dinghy as depicted above, lol) and He spoke to the crowds. Note, He was sitting, they were standing, indicting His important presence.
Were they thirsting for the truth from the Living Waters? Or were they rubberneckers hoping for a personal miracle? Both. We know the end of the story, most people turned out to be rubberneckers only out to see the latest thing in Galilee. Most of these same people eventually rejected Him. (Mark 6:4-5).
What a momentous occasion on that shore! To be present and taught directly by God Himself. We are blessed, we believers in this present Church Age. We have the Holy Spirit in us to teach us these things. This Spirit will never leave us.
Nevertheless, I tell you the truth: it is to your advantage that I go away, for if I do not go away, the Helper will not come to you. But if I go, I will send him to you. (John 16:7)
The blessings from our Lord are manifold, beginning with our indwelled Spirit, and His word which was later written down at the inspiration of His Spirit. Study His word today, worship Him by praising Him for those words, and bless Him by being obedient to them. He is a gracious and magnificent God, who taught His sheep from the boat.