Yes to nitrox - if you don't use it now, you will in the future. Having said that, we dove with Rainbow Reef last month and had one dive that was 90 ft (the Spiegel), and another that was 77 ft, (a deep drift on Molasses). Other than that, here are the depths of my dives (FWIW): 40, 32, 28, 34, 23, 40, 30, 41, 43, and 51 ft! We knew, the day before, when our 'deep' dives were going to happen, so we could have opted for nitrox on just those dives. Most days we basically had no surface interval (19 minutes, 28 minutes, etc) as the dive crew didn't feel it was necessary with such shallow dives. We dove nitrox in the hopes it would help keep our energy level up (we're a little older - and yes, I understand there's no absolute proof this actually works, which is why I said 'in the hopes' it would help).