The Cayman Islands Watersports Operators
Association dictates to its membership how deep
tourist divers may dive. Its policy is: “The recommended
maximum depth limit with SCUBA
customers is 100 feet. The required maximum depth limit with SCUBA
customers is 110 feet. ”
 The CIWOA is a voluntary association — not a government
  organization — to which nearly all the major dive operators belong. Its
  rules, as least those posted on its website at www.cayman.org/ciwoa, don’t
  specify time limits for second dives, the number of dives, nor the surface
  interval, but they do prohibit decompression diving. The depth rule was
  developed before computers to ensure safe diving.
 The depth limit is not necessarily problematical. Time limits that
  don’t account for computers are. Nevertheless, virtually all the
  operators on Grand Cayman set depth and time limits: 100 feet for 30
  minutes, then 60 feet for 40 minutes. Many computer divers, especially
  photographers, feel ripped off by such restrictions. But, you get back at
  a pre-agreed time, so you and the divemasters can sit down for lunch —
  and the boat can be turned around for the afternoon dive.
 So, if you want an operator that gives you more bottom time, refer to
  the Travelin’ Diver’s Chapbook to see who fudges a bit, then see what they
  tell you via e-mail or phone. Some to consider include the Cayman
  Diving Lodge, DiveTech, Dive’n Stuff, Cayman Marine Lab and Red
  Baron. On Little Cayman, the Southern Cross Club and Pirates Point.
  And, of course, the Cayman Aggressor.