Dear Scubafanatic,
Being an instrumentation engineer for many years, I was thinking of bringing that up. Almost never are any two gages in perfect agreement…even very expensive laboratory ones which are much better than the ones bounced around with scuba gear. So some who think they always get short fills, or over fills, may more properly blame their own gages—and digitals are no better.
The same very basic concept of instrumentation holds true for water temps which would probably explain some conflicts on that issue. Indeed who really should expect their water temp readings to be better than plus or minus 2-3 F.
Dave Dillehay