Messing about on the river ...

When the weather is fine then you know it's a sign
For messing about on the river.
If you take my advice there's nothing so nice
As messing about on the river.
There are long boats and short boats and all kinds of craft,
And cruisers and keel boats and some with no draught.
So take off your coat and hop in a boat
Go messing about on the river