Fig. 2: There is a reef around Rarotonga, about 100-200m out to sea and only 1.5-1m deep. This is where the waves break, which hit the island unhindered from all over the Pacific. Snorkeling that far out is unhealthy. You're either smashed against the reef or you can't make it back. Rarotonga, Cook Islands Nikon D200; Δt=1/1000 s; f=400 mm; f/5.6; ISO 200; 6 July 2010 21:09:11