Sounds about right, that is until your body becomes acclimated to the conditions at your locale. DUI is great about educating divers on temperature safety. AFter all, if you`re in water colder than your body temp, you`re already in the earlieast stages of hypothermic exposure in a manner of speaking. I`ve often found myself diving w/o wetsuit 70 degrees and above. I don the 3mm tropical full any colder and the 5-7mm farmer beyond the 55-60 degree mark. I`m good in the farmer to 45 degrees, but my time is quite limited w/o a dry suit at that temp.