The article presents the story of the Rolleimarin 504 underwater camera housing. The topics discussed include the Rolleimarin's production and introduction by camera manufacturer Franke & Heidecke and filmmaker Hans Hass in 1954, the auction of an old 504 on eBay in 2011 won by Dr. Andrés Clarós, and the project to restore the old 504 thereafter. The first international conference about the Rolleimarin and underwater photography held in 2012 is also discussed.