Common myth that freediving snorkels interfere with hoses. The main reason for this myth is because scuba divers w/ bad freediving skills push their snorkel butt up to the mask frame, where as divers with good freediving skills will push the snorkel back along the mask strap, using a snorkel keeper as an attachment. Doing this allows any snorkel to stay out of the way, and allows the snorkel to come straight and clean into the mouth when needed.
With this method you don't need a flexible corrugated tube on your snorkel which is only needed when you push the snorkel butt up against the mask frame. With the snorkel pushed up to the mask frame, the corrugated tube allows the snorkel mouthpiece to fall clear of the hoses, where as the curve of the standard J-snorkel will hook onto hoses. With this configuration, the corrugated hose allows the bottom half of the snorkel to twist and curve into the diver's mouth. This corrugated tube however is still the bane of many diver's entanglement issues, which is why a lot of divers say to ditch the snorkel after class (how's that for wasting money?).
With the snorkel pushed back along the mask strap, the mouthpiece (J-type or corrugated hose type) will be at your clavicle and clear of all hoses. With a snorkel keeper used as an attachment in this configuration, you'll be able to pivot the snorkel so it can come clean and straight into your mouth.
With this configurations, the corrugate hose becomes a gimmick that's not needed at all. It serves no purpose.
Dry snorkels can become jammed with large sand, restricting air flow entirely (depending on the beach this could be very likely to non-existent).
The top dry valve also has a smaller orfice for air compared to a regular splash guard or plain snorkel. It also takes significantly longer to blast clear than an open top regular snorkel.
Splash guard snorkels are nice, but not a necessity if you practice good skin diving skills.
So for a snorkel, get a cheap J-valve snorkel, purge or no purge. I prefer no purge because it means you can blast clear as hard as you want. With purge snorkels a big blast clear might go out the bottom of the purge, meaning you have no air and still have all that water in the snorkel. A normal teen and adult will have enough lung power to blast clear any snorkel w/o a purge. With purge snorkels you often have to focus on using a light purge to really effectively clear the snorkel; this may sound ideal (using a light purge) but when your stressed it's very hard to control (ie during high waves, when you're winded, or when you're running low on breath).
Masks are a different story. 2 pane masks tend to be less volume than 1 pane. Meaning it takes less air to clear your mask if it's flooded.
1 pane tends to have a bigger peripheral view than 2 pane, but this can change depending on the manufacturer. You do NOT notice the "blind spot" in the middle of your mask on 2 pane masks, unless you go cross eyed.
The most important thing about a mask is the fit. You should be able to hold the mask (w/ no strap) on your face by breathing in through your nose (using suction alone). A stellar fitting mask will have no gaps between your face and the skirt when you just lay it on your face, head tilted up. (once again, no mask strap, but no suction this time)
Clear VS Black mask
Clear allows more light in, which can create glare, but a feeling of less claustrophobia for some. The glare can be annoying if you're trying to use a camera or view into a dark nook for sealife.
Black mask take away this glare, but can give you a feeling of claustrophobia. If you're not claustrophobic, then it shouldn't matter.
I prefer black mask because during sunny days you're not constantly squinting on the surface. The mask can act like a visor against the sun if you turn your head the right way.
Purge or no Purge mask
Like snorkels it isn't necessary. Some may like it, preferably those who breath out their nose when diving. It can make mask clearing easier, but it can also fail because of sand. Just like with purge snorkels, over purging can force all the air out and still leave water in the mask. You have to force yourself to not purge to hard
Side Viewing panes or standard
Side viewing panes adds just a tiny bit more peripheral viewing room for your, but makes the mask very high volume. Unless you prefer to strain your eyes (VS turning your head) when you want to look sideways, then forget about this option.
---------- Post added April 9th, 2012 at 10:18 AM ----------
Snorkel examples that I prefer are soft, not made of plastic but with a flexible synthetic, and no purge, corrugated hose, or other gimmicks:
Cressi Corsica
View attachment 120936
Riffe J-snorkel
View attachment 120935
Mares Pro flex
View attachment 120937
Many other manufacturer's still make standard J-snorkels. Feel free to mix and match with your mask.