Mark 4:1
And he began again to teach by the sea side: and there was gathered unto him a great multitude, so that he entered into a ship, and sat in the sea; and the whole multitude was by the sea on the land.
Cross-reference
In Mark 4:36, the same boat is used for crossing the lake, linking the teaching scene to the subsequent journey.
Mark 2:13 describes the same pattern: Jesus teaching by the sea with crowds gathering. This strengthens the motif of Jesus' lakeside ministry.
Matthew 13:1 is the direct synoptic parallel—identical setting: Jesus by the sea, large crowds, getting into a boat. It's the same event.
Matthew 13:2-9 is the parallel parable account following this setting. It provides the same teaching from the boat.
Luke 5:1-3 shows a similar scene—Jesus teaching from a boat—though likely a different occasion. It reinforces the common teaching method.
Luke 8:4-8 parallels the same parable of the sower narrative, with the same setting by the lake.
In Luke 5:3, Jesus also teaches from a boat, likely the same event or a very similar setting.