On the milky margin drifts
a ship, rocking like a tired soldier,
war-torn and indifferent beneath
the gauzy halo of the moon
From the shore I watch her lurching,
a to-and-fro motion that sets me dizzy
until my vision is a narrow tunnel
wrestling with the raging sea
Frothing, the mighty beast
licks her heaving wooden sides
and I wonder at her fortitude,
which is more than I can manage
On the sand I am steady, sheltered
and yet I feel the deck beneath my feet,
battered and buffeted I brace for ill weather
and watch the clouds closing in
Sarah Williams, USA
The Social Poet 
wow- i live at the beach and have had the sensations you describe numerous times- it is wonderful and your imagery and phrasing is true to the experience