I don't believe that most folks own 45, much less 70 pounds of SCUBA equipment. The 70# thing is a holdover reference from ancient history. Airlines were trying to accommodate the popular sports, some of which were diving, skiing, golf and surfing.
The people that formulated the industry rules knew not much about diving, nor the realities of dive travel. The rules have never evolved with current realities. They wanted to make sure divers would fly the new airline routes to "the islands", so they figured out that a diver's gear must include fins, mask, "a single" regulator, speargun, plus a 72 cf tank and 12# of lead weight. Voila, 70#.
There are some new airline regs specifically about "tanks", but those fall under a seperate heading from "sports equipment". They have to be shipped "open" which means nipple removed and not even tape over the hole.
Sometimes.
If you do this, you should also likely note that any such tank is, by industry standard, to be professionally re-inspected and cleaned if necessary before reassembly and use.
Some people actually ship their "soft weights" in their luggage. These are made with #7 lead shot as used in bird hunting, wrapped in a ballistic nylon pouch.:eyes:In that this contains what is precisely a prohibited item, "ammunition or components", it is also a theoretical felony.
So there's that.
So, if you're going to stamp your feet and demand a full 70 pounds of baggage, you might get ready for some very sharp manager who fully understands the context and wording of the rules. If it isn't on their list of what constitutes SCUBA equipment as they define it, good luck on that one. Canister dive lights, extra standard alkaline dive light batteries, and underwater cameras have been disallowed previously.
If you really feel mean and want to get into a memorable fight, bring a rebreather along. Pack a lunch while you're at it.
IT DOES NOT MEAN that you can have a 70# bag if it also has "some dive related gear" combined inside it along with your 6 pairs of high heels, etc, etc.
It's all about getting you to buy that second 50# bag, this is the end-game standardized goal to which the front line airline personnel have been trained to.
Resistance is futile. You will be assimilated. We are Borg.
Unless you are currently what passes for royalty in the USA, that is, you have "points", then you can do anything short of playing bocce ball in the aisles. Stewardii are still off limits.