> > Well, the vis in Stoney was upwards of 10 metres. The top of the tugboat is 15m down and at one point you could see it from the surface. A marked contrast to my open water cert dives. I had about as much vis as you did although as it was a lake I had no current to contend with. But mask clearing was interesting as it didn't seem to make much difference whether I was wearing it or not! I am jealous of my brother who learnt NAUI while he was holidaying in Australia and dived on the GB reef. Talk about clear water!
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> Beasty

The best vis I've ever had was on a trip to Vanuatu I went on for work. Tropical diving is wonderful. In New Zealand we can get 20 metres or more on a really good day, depending where you dive, but I've mostly experienced around 10-15. Of course, the possible minimum is "nothing", same as anywhere else. Waikoropupu Springs in the Nelson district is reputed to have the best vis in the world, something like 65 metres. You can't actually see the water - looking down into the spring from above, or in photos, divers appear to be floating in midair.

The spring isn't anywhere near 65 metres across, but they measured the vis scientifically somehow. The Department of Conservation monitors it strictly and you have to get a permit to dive there, to prevent too much human interference from ruining the spring.