AL 40 recommendation?

[Marie13]

Why?

According to what I see in his profile, he is beginning tech. For most shallower tech dives, AL 40s are an excellent choice, and an AL 80 would be too much. If he gets into more serious tech diving, AL 80s will be needed, but in that case the AL 40s will still be used as well.

Just ignore the troll.

 

[Alaskan Scuba Dude]

Advantages and disadvantages of using an AL40 opposed to using an AL80. Dive team may not have sufficient gas to finish their staged decompression in an emergent gas loss. When penetrating difficult wrecks an AL40 has proven useful as a backup when using doubles. Center of gravity (buoyant force) is not noticeable for recreational divers. Great when standing, kitted up with doubles, two AL80s and one AL40, at the platform while the skipper maneuvres the boat into position. Center of gravity on an AL80 can be altered by moving the stage straps further apart or using a choker. Buoyant force on an AL80 becomes insignificant on the ascent due to decompression obligations. Resale value is better on an AL80.