* Prices may differ from that shown
I currently have a range of 4 hoods for scuba diving and surfing. I bought this one quite a while ago and have found it fairly uncomfortable compared to others. It serves it's function of keeping your head warm, but I would advise going for other brands as described below.
--Why a hood ?---
The body looses a large amount of heat through the head. Diving or surfing in the UK is obviously pretty cold (I have found it coldest at the start of the scuba diving season in april when the water reaches about 7 or 8 degrees celcius at 20m depth). In addition to providing comfort by wearing a hood, by being less cold and more comfortable you find that your air lasts longer and means that you can dive for longer.
When surfing the surface water doesn't quite reach the same low temperature, but it is still cold and I tend to surf for longer than I dive. A hood also stops the 'brain freeze' when an ice cold wave slaps you in the face.
The only disadvantages of a hood are a) it restricts your vision and movement a bit and b) it makes you look even more like a seal (don't go near great whites..they are known to bite scuba divers in wetsuits mistaking them for seals)
--The Mares 6.5 mm Trilastic Hood----
The Mares hood is aimed at scuba dives as Mares are mostly a dive manufacturer. They generally make good quality mid-range items and you find a lot of dive schools around the world use Mares equipment for training newbies. The hood is just as suitable for other watersports in cold wate as for scuba diving.
The mares hood is 6.5mm thick around the head and has a 'skirt' of 3mm that tucks into the top of your wetsuit. The skirt is an excellent feature to include as it lowers the amount of 'flushing' where cold water flushes through your wetsuit taking body heat with it.
The Mares hood is made from Tri-elastic. This means that it has 5mm 'high compression' neoprene around the top of the head, 3mm Sapphfire skin around the face and 3mm 'standard' neoprene around the skirt. The neoprene around the neck and side of the head is 'stretchier' than the rest of the hood making it easier to poke your noggin in and out.
The hole for your face is supposed to fit from above your eyes to just below your bottom lip. I find that it just about goes in the right place, but is very restrictive around the top of the neck and around the chin. I wear the XL size (as my head is pretty big) and sturggle to get my mask to seal against my face without the hood getting in the way.
The mares hood sells on amazon for £43.95. I would call this expensive compared to other hoods and would shop around for something closer to £30. I believe I paid around £20 for a 3mm O'neil hood and £28 for a 6mm (but I could well have got these through ebay...I don't remember)
For surfing I prefer the 3mm O'neil hood that I own which incorporates a visor to protect slightly from the sun (when it appears). I find this thick enough for warmth at the surface of the sea and the thicker hoods feel cumbersome and restrictive.
When Scuba diving I've now invested in an otter drysuit which includes a hood. It is similar to the mares in that it is stretchy and a similar thickness, however I find the face hole far more comfortable and less restrictive.
In summary I dislike this hood. It keeps you warm, but is uncomforatble to wear. It may suit you're head shape better, so I would advise trying it on in a dive shop before buying. It is expensive and I would advise going for a different brand (scubapro are normally good quality and a bit cheper...but I haven't tried their hoods)
I'll still give it two stars as it may fit other heads better and it does keep you warm well which is the most important function.
Mares Hood 6.5 Mm Trilastic. - Trilastic mix: low compression neoprene on the top of the head, 3mm inside Sapphfire skin in face, and 3mm bib. - Super elastic neoprene at the neck and side of the head for easy entry