I know there are many opinions about gear, what is needed what is not, what somebody just can't live without, while somebody else thinks that's silly, etc etc etc....
Some examples of gear I've seen mentioned as being gimmicky (not necessarily my opinion):
Spare airs
Split fins or other fins with gizmos like tension traps, whiskers, odd shapes, etc.
Expensive reg sets
Tank bangers
Ankle weights
Colors of any kind
Certain BC's
Certain models of drysuits
Sidemount
Consoles
Big snorkels with check valves and ball valves
Big giant knives strapped to legs
Hoseless wireless computers
Computers in masks
Computers in general
Anything else you think is gimmicky?
Spare airs,
non paddle fins
expensive regs are kind of up in the air, certain ones are justifiable, most aren't. Poseidon, Atomic, Apeks, Scubapro can justify some of theirs for certain reasons, but some are insane
tank bangers
ankle weights
colors not so much, nothing wrong with them
all backmount bc's that aren't a modular BP/W system, includes Zeagle
I don't know of any drysuits I'd consider gimmicks
sidemount is a very useful tool for things like cave diving, but the UTZ Z-system is a gimmick
consoles are nice if you have just a depth gauge and SPG clipped across your chest to have everything right there for "reef b!tch" type dives, but with computers as cheap as they are, yes
any non-J snorkel. I do like my flex hose, no dry caps or valves, this includes masks with those stupid nose valves
depends on the knife, sometimes there are uses, mainly in working dives in the ocean but they are dive tools, not knives
all AI computers at this point. The exception would be the SeaBear HUS that has wired AI for FFM diving. Wireless is a waste
yes
computers are really helpful for sawtooth diving and working dives, but most importantly those that let you choose your GF allow you to custom tailor your conservatism. With tables the NDL's are around GF95, which is way too high for any sort of technical diving and if you are prone to getting bent, you can knock off the tables and come up early, but you're shooting in the dark for your actual tissue saturation. Recreational computers without user settable gf's, yes, but not the "real" computers
added to the list, not necessarily gimmicks, just ridiculous products
AL100's
Neutral buoyancy 80's
padded backpads for backplates
wrist compasses, use a slate if you want to navigate somewhere, more useful and accurate.
retractors of any kind
pistol grip lights
slap straps *unless you have long hair*
most manufacturers "octo's"
Air2's
pull dump inflators
that lever nonsense they're putting in BC's
silicone suicide straps
Hollis Explorer
Poseidon rebreathers
recreational DPV's
Dive Rite LX20
all Light Monkey can lights
Hollis SMS-50
I'm sure there's more....
Things I disagree with
Heated vests, that is one of the best things to improve diver health and safety.... Don't bash them, they are infinitely better than any other development in exposure protection since the first trilam and crushed neo drysuits. It literally trumps any innovation in undergarments.
Digital compass-it's a cheap module that is more accurate and easier to use than the big floaty compasses
High output lights, nothing wrong with them, especially for video and cave diving, no reason not to have them now that the technology is there. In open water sure they're a bit excessive, but in the environments they were designed for, they're immensely useful.