This is a verse from the quatrain "Crossing the Lake" by Yu Gui, a poet from the Song Dynasty.
The whole poem is:
The boat moves to the other shore and the water lines bloom, the sun is warm and the wind is fragrant, and the plum blossoms are falling.
The mountains are misty and horizontal, and white gulls fly everywhere, bringing poems.
This is a landscape poem, describing the beautiful scenery seen while boating on the lake.
It means:
The boat moving to the other side makes gentle water ripples on the lake.
The plum blossoms are falling and the sun is warm and fragrant.
The misty mountains in the distance are like a horizontally unfolding picture scroll.
The white gulls flying from time to time in the sky bring infinite poetry.