Just looking at the poem's basic structure shows the reader that the poem is organized in 2 line stanzas called couplets.
The poem has rhythm and rhyme. Each couplet follows the rhyme scheme of AA BB CC DD and so on. Most of the poem is written in the iambic foot, but no set meter is established. Some lines have 8 beats and others have 12.
Similes are used. "Take flight like a bird" is a line that describes what the swimmers look like as they hurl themselves away from their starting blocks. "Legs churning up water like crazy eggbeaters" describes what the entire scene looks like as the swimmers give the final push to finish the race.
"Swimmers surge" is an example of alliteration. The second stanza also contains alliteration with the "positions pose" line.
The author also does a nice job of building suspense in the poem. There's a slow build up to the fast finish of the race being described in the poem. "Start swimming in a steady crawl" leads to "churning up water like crazy eggbeaters" leads to "great tensity" followed by "surge towards" and "wild shouts erupt." The reader can't help but lean in and feel the suspense of not knowing which lane is going to win the race.
Literary devices present within the poem are imagery, simile, rhyme, and alliteration. There is not much of a hidden message to the poem since they are describing a swim meet. However, the speaker feels so much enthusiasm and is so into it that he or she cannot contain their excitement as they describe it. In this case, tone can also be seen as a literary device.