However, the diving in Chile looks excellent - the prevaling Humbolt current keeps the water pretty cold (it aint coral reef), but means the sea life should be rich. It might be well worth trying to get out to the Juan Fernández (Robinson Crusoe) Islands. Viña Del Mar and Valparaíso, both on the coast close to Santiago have dive centres, try Google searches on combinations of 'buceo' 'chile' 'Viña' 'Valparaíso' etc. A very quick starting link that seems to have some good info: website Didn't go to the coast in Peru, but I'd be surprised if there wasn't 'something' in Lima.
Also, is it possible (as in are there dive centres there) to dive in Lake Titicaca in Peru ? I'm told the archeology there is very impressive and Jaques Cousteau did a few dives there. No dive centres, as far as I could find out. If you do manage to mount an expedition to get full gear, tanks, weights and a compressor up there, please do send a trip report! At 4,000 metres, it is an altitude dive beyond most deco models, so be careful! ;-)
Facts about Chilean Expedition diving

• It is in Chile
• Chilean Expedition diving is in the Pacific.
• The typical depth is 0-20 Metres 0-60 Feet.