John Lennon provided the distinct "bubbling effect" on the song used to create the sense of a submarine going underwater. Lennon used a straw and blew bubbles into a pan of water to create the effect.
Lennon again was involved, along with Paul McCartney, in creating the voice of the captain giving orders heard at different intervals of the song. The group's primary songwriters both talked through tin cans to get the detached, "phoned-in" sound of the captain's voice.
A pair of Abbey Road employees twirled chains in metal bathtubs to achieve other submarine under-the-water sounds during the recording.
The band ransacked the cupboard in the studio's storeroom for the items used for special effects. These included whistles, chains, a ship's bell, tap dancing mats, a wind machine and a cash register.