The Thames of the title is a tidal river, and Dave Bonta's six lines start from the simplest thing a tide does: it arrives, lifts one hull after another, and moves on. "The tide went from ship to ship" sounds almost like a log entry, plain and rhythmic. Then the poem turns the water into a person, and it becomes stranger and more fun. The tide is "like a captain at the tavern / calling at a room / where there was infinite cake." Nothing in the poem explains why a tavern should lead to cake, or what the cake stands for. It simply trusts the reader to go along with it.
The phrase "calling at" does a lot of work. Ships call at ports, and people call at houses, so the verb belongs to both worlds at once. The captain is a sailor stopping at a harbour and a visitor knocking on a door, which is exactly how a tide behaves as it touches each vessel in turn. The comparison also gives the water a mood. This is a tide that wanders, sociable and a little tipsy, going wherever the good things are.
Those good things are the most surprising part. A tavern suggests drink, so "infinite cake" is a small shock, a childish, abundant sweetness where we expected ale. "Infinite" is also the only abstract word in the poem, sitting among ships, rooms and reeds. It stretches the scene beyond anything a real room could hold, and it makes the captain's visit feel like a dream or a story told to a child. I read it as a hint that the river, for all its ordinary traffic, feels boundless and generous. That is an inference from the imagery, not something the poem states.
The sound of the lines supports this. There is no end rhyme and no fixed metre, but the lines are short, roughly five to eight syllables, and they move with an easy, lilting pace. Hard *c* sounds run through the middle of the poem: "captain," "calling," "cake." They link the captain to his destination, as if the sound were a path he follows. Earlier, "ship to ship" repeats a word and a sound, so the line itself hops from one vessel to the next. The soft *w* of "water" and the long vowel of "reeds" slow things down near the end, and the last words of the final two lines, "reeds" and "bed," faintly echo each other with their closing *d*.
The dash after "cake" is the hinge of the poem. Before it, we have a complete sentence with a subject, a verb and a simile. After it, the grammar falls away: "water in the reeds, / a voyage into some bed." Neither phrase has a verb. The sentence loses its engine just as the tide loses its force, and the poem drifts instead of marching. The reeds put us at the river's edge, in shallow, quiet places, away from the ships in the channel. Then the word "voyage" brings the nautical language back, but the journey now goes down and inward rather than outward.
"Bed" is the richest word in the poem because it works on two levels. The tide settles into a riverbed, which is literal. It also settles into a place of sleep, perhaps after the evening of tavern and cake the poem has imagined. The indefinite "some bed" keeps the tone casual and a little drowsy, as if the captain no longer cares where he lies down. Read this way, the poem follows a whole evening in six lines: arrival, indulgence, and sleep.
What makes the poem worth reading is how much it does without naming anything. It never mentions London, a bridge or a landmark, and the title alone places us on the Thames. Everything else is metaphor, and the metaphor does the work a description would normally do. It shows the rise and fall of the water, and it gives the river a character, a mood and a plot. It also shows that a poem can be both playful and quietly moving. The humour of the cake and the tavern lightens the opening, and the closing images of reeds and a bed leave a calm, almost tender feeling. For students, the poem is a good example of how a few well-chosen words, an unexpected comparison, and a grammatical break at the right moment can make a familiar natural process feel new.