That would, in fact, be Cayman Brac and Little Cayman, sometimes known as the "Sister Islands." The diving at Little Cayman is spectacular, the diving at Cayman Brac is a little less spectacular. It's still fairly expensive, but I think less expensive than Grand Cayman. Check out Little Cayman Beach Resort and the Brac Reef Beach Resort. They have the same owner and dive operation. Rates are pretty reasonable. We were at the Brac Reef a few weeks ago and it was great. When you look at the rates, consider that tips for the housekeeping and dining room staff are included in the rate. Their packages usually include three boat dives a day. Shore diving is possible, but there really isn't any access from either of the resorts themselves. A rental car would really be necessary to get to the good access points. We decided it really wasn't worth the aggravation and expense.