There were/are 3 bands known as The Deep Six.
1) A rock band of Christchurch, New Zealand. Est. 2011.
2) A folk-rock ensemble formed around 1965 in San Diego, beginning as a folk group and hastily electrifying their music as the folk-rock boom began. They released an album in 1966, including a cover of Neil Diamond's Solitary Man, some light pyschedelic/garage rock touches, and a whole lot of session musicians. The album and singles flopped ("Rising Sun" got some airplay) and the band broke up shortly afterwards. Read more on Last.fm