Stanza one
The poem begins with an unusual sentence structure: two infinitive clauses, To stub an oar on a rock鈥o have it rise.
The effect is to create a tension and suspense until the meaning is completed by the poet saying this is a thing that happened once (too often)
to him.
The opening tension increased to with the mention that there is a rock where none should be,
followed by the startling assertion that this 鈥榬ock鈥 rises with a slounge out of the sea
.
The use of rock
suggests the hardness and immovability of the object met. The neologism (new word) slounge
seems to be an amalgamation of 鈥榮louch鈥 and 鈥榣ounge鈥, and conveys the slow, lazy, ponderous movement of the surfacing creature it describes.
The alarm caused in the poet is neatly shown with the humorous parenthetical aside (too often)
implying this is not an encounter he wishes to repeat. The slow, steady rhythm of these three lines is perfectly suited to the gradual surfacing movement of the huge shark.