This poem is from "Fringes of the Fleet", the first series of articles in what became Sea Warfare. The poem was one of four (later five) from that work which Edward Elgar set to music in a song cycle; score available at Google Books.

See this message I posted previously in a "tunes for Kipling verses" thread for further information and links:
http://mudcat.org/thread.cfm?threadid=138945#3182880