Hoods Hoods come in many thicknesses and sizes and for a novice person is it tough to figure out just what you need. There are a couple of features that you should be looking at when it comes to gloves. Below are some of the more important deciding factors. Thickness Hoods come in everything from 1mm beanie to 7mm and above. The thicker the MM (millimeter) the warmer the hood is going to be. For warmer waters most divers go with a 1mm beanie to 3mm hood, for temperate 3 to 5mm and for colder waters 5 to 7mm. This is not a hard and fast rule as everyone out there is different. John’s Quick Tips; Hood Types Beanie Beanie hoods are usually 1mm but can be found sometime in just a poly pro material. The beanie hood is common in warmer waters to keep your head warm. It fastens underneath your chin and leaves your neck exposed. Most beanies also cover your ears. Bibbed Hood This is the common hood you see wetsuit divers wearing. They are also called tuck in hoods. This hood is looser around the neck area and for most divers the better choice. I however am one diver who does not like them. The extra material always felt awkward to me and if you do not get it laid down right it can be down right bothersome. No bib This style uses a tighter neck area to keep water from flushing. The only down side with this version is if you wetsuit is loose around the neck are the hood can allow water to come in and cause a cold spot.