The crowd that has been following Jesus caught up with him.
He took to the water and spoke to them from a boat.
The analogy of a resultant massive catch of fish,
is used to describe the impact on the crowd,
the fish being the followers converted
to a new understanding of life.
Why is this not explained in more straightforward terms?
Who do the writers use analogy and parable?
Maybe to conceal the radical nature
of the content of the message
that Jesus preached.
Maybe to disguise the impact of the message,
the numbers involved in the gathering,
the size of their local support,
the manpower for revolt.
Maybe to protect later followers
from the revenge of the authorities,
those "cleaning-up" afterwards.