Weather check please.....

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Ignoring your snark, there are no good and cheap thermometers to use underwater. You just need to calibrate them (like in a dishpan in the kitchen) with a good thermometer as a standard and make your adjustments in your log as needed. I've done that to maybe a dozen dive computers, including Shearwater, Oceanics, Dive Rites, Sensus, Zeagle, and my wife has done the same including her old Casio diver's (digital) watch. You need to allow for the thermal time constants to settle out.....a thermistor embedded in a lot of plastic doesn't respond very quickly to a change in temperature....10-15 minutes might be needed for a good calibration. I use a cook's Thermapen for my standard, and even though it is expensive, it is still only rated to +/- 0.4degC, or about 1degF.

Results? Her Casio watch is very good....just an accident....maybe within 0.2degF of the Thermapen. the worst I ahve is the Oceanic OC1, at almost 4defF low. The Sensus is quite good, within 1degF, but you have to download it to read it; it is spec'd to +/- 0.8degC.
 
There is a difference in most diver's temp gages but it is sure to be no worse than between 78 F and 82F. Down to a solid 78-79 in January, then up to 85-86 in Summer. Pretty darn repeatable for 25 years that I know of. Transition months tend to be Nov-Dec and April-May but a 5-6 degree spread is not very much.

If you are lucky enough to enjoy dives longer than 1 hour it will take a little more neoprene no matter when you dive. For me, a full Lavacore Skin works year round but a 3 mil shorty join top is enjoyed when it is 78F.

Dave Dillehay
Aldora Divers

PS MMM mentioned that it rained heavily in Playa Del Carmen (10 miles away) today yet my Texas Rock rain gage indicated no rain all day here.
 
Last edited:
Changed summer temps to 85-86 NOT 75-76

Dave
 
Perhaps the Texas Rock rain gage technique would work underwater. If you are shivering: it is too cold, if you are sweating: its too hot!
 
flyboy08:
HA, why yes I would..not arbitrary, but a fellow member here such as Dave...thank you Dave. I took 4 years of meteorology and the best observation/forecast comes from the ground at the location:)..Of course, I can pull up the charts and start forecasting myself, but I would come up with the same predictions the web offers:)...
Click to expand...

We can tell you what current conditions are at our location on the island - but that is not going to tell you what it's like 2 or 3 miles down the coast and we aren't forecasters so can't tell you what it's going to be like an hour from Now. we use the same tools and information that are available to you as Dave posted - I think those two sites are what most of is use.

The only accurate report I can tell you is that we are in the tropics - its hot, humid, and the weather can change on a dime.
 
tursiops:
Ignoring your snark, there are no good and cheap thermometers to use underwater. You just need to calibrate them (like in a dishpan in the kitchen) with a good thermometer as a standard and make your adjustments in your log as needed. I've done that to maybe a dozen dive computers, including Shearwater, Oceanics, Dive Rites, Sensus, Zeagle, and my wife has done the same including her old Casio diver's (digital) watch. You need to allow for the thermal time constants to settle out.....a thermistor embedded in a lot of plastic doesn't respond very quickly to a change in temperature....10-15 minutes might be needed for a good calibration. I use a cook's Thermapen for my standard, and even though it is expensive, it is still only rated to +/- 0.4degC, or about 1degF.

Results? Her Casio watch is very good....just an accident....maybe within 0.2degF of the Thermapen. the worst I ahve is the Oceanic OC1, at almost 4defF low. The Sensus is quite good, within 1degF, but you have to download it to read it; it is spec'd to +/- 0.8degC.
Click to expand...


Thanks for outlining. Nice and straightforward, I'll give it a go. Would it be safe to assume they are linear once calibrated?

Maybe another thread for this topic as I think some people would enjoy a more accurate temperature reading who aren't lurking this thread.

Thanks again for sharing,
Cameron
 
northernone:
Thanks for outlining. Nice and straightforward, I'll give it a go. Would it be safe to assume they are linear once calibrated?

Maybe another thread for this topic as I think some people would enjoy a more accurate temperature reading who aren't lurking this thread.

Thanks again for sharing,
Cameron
Click to expand...
Linear? Good question!
No, not especially, which is why you want to calibrate them near the temp at which you want to use them. Therefore, even if the computer might withstand 0C and 100C (I doubt it), I would not calibrate with ice and/or boiling water because you are likely to be using it around 20-35C.
 
Warmer and more wind today.
 

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