Promptly 4, 5 and 6

Shoreline

Shoreline

Two words
setting the scene,
with each line adding two,
aiming at the total of eight,
before the wave retreats
by two each time
to two.

Two too,
the wave grows
from two to six and eight,
spreading on the sands of meter,
this constant flow and ebb
the breath of seas
in twos.

Line count: 14
Form: Eintou, seven lines with syllables counting 2-4-6-8-6-4-2, repeated to total 32 syllables in all.
For Promptly Poetry Challenge 6, Week 15
Prompt: Write an eintou.