Four short lines, and the first doesn't bother with a verb. "A port to drink in" reads like something muttered on arrival, a sailor's relieved shorthand for the only plan that matters once the ship is tied up. The title, "Shore leave," sets that scene: time off the water, permission to step onto land. The poem then turns the scene inside out. It is the fish, not the speaker, who go somewhere else.
What the fish are is the poem's puzzle. Read literally, they could be the day's catch, the smell and slime of work that clings to a head and hands. But "fish" in a *head* suggests something less physical: thoughts, worries, ideas, the slippery, flickering things that never stop moving once you try to hold them. Nothing in the poem tells us which reading is right, and the poem seems happier that way. Judging by the imagery, the speaker's mind and body are being pictured as a kind of water, and the fish are whatever has been swimming in it.
The central idea is release, and the poem's small joke is that this release is not an achievement but a handing-over. The speaker doesn't drive the fish out. They simply leave, and the speaker is left empty and at ease. The first line helps explain why. "A port to drink in" puns quietly on "port," both a harbour and a fortified wine, and "drink in" can mean to absorb a place with the senses as well as to get drunk. Shore leave becomes a double emptying and filling: the head clears of one thing and takes in another.
The most interesting moment is the line break after "and hands to." The sentence could be read two ways. The fish left my head and hands, departing for their own sea. Or the fish left my head and hands *to* their sea of mischief, abandoning the speaker's thinking and working parts to the sea's whims. The dangling "to" at the end of the line lets both meanings float. The word "left" also echoes "leave" in the title, so the poem plays on leave as permission and leave as departure. The speaker is granted leave, and the fish take leave.
"Their sea of mischief" is the poem's richest phrase. The sea belongs to the fish, not the speaker, which gently admits that the mind's restless activity has a home and a will of its own. And "mischief" is a surprisingly light word for something so large. It makes the sea sound less like a danger than a playground, where thoughts are naughty children rather than threats. The sound of the word also pulls it back toward "fish": the short "i" and the "sh"/"ch" endings chime, so the creatures and their element feel linked by sound as well as sense. The same short "i" runs through "drink," "in," "their" and "mischief," giving the poem a quick, slightly giddy tone.
The construction is spare and quiet. There is no rhyme and no punctuation beyond the full stops, but the rhythm is not careless. Three lines have five syllables, and the third, "and hands to," has only three. That short line is like a stumble on the gangplank, or the half-beat before letting go, and it tips the reader into the last line. The consonants of "head and hands" add a soft, repeated breath, an h-sound like an exhale.
What makes the poem worth reading is how much it holds in so little space. It sketches a whole situation, a worker or wanderer arriving somewhere to rest, then suggests that the real destination is an unclenching of the mind. It also avoids the usual sermon about relaxation. The speaker doesn't announce peace or reflect on stress. A fish simply swims off and a drink is waiting. The poem trusts its images, and a reader who looks closely finds more than four lines would seem to hold.