We traveled EgyptAir from Hurghada through Cairo last week at the end of our Red Sea liveaboard trip. In my backpack I carry a Gopro camera with video lights, several dive computers 2 regulator sets, a tank fill whip, 360 degree tank lights for night diving, several dive torches, charging packs for phones, a laptop with charger, and chargers for dive lights and the camera. The backpack is heavy and fully loaded.
The security screening was the most thorough I've ever experienced. The screener took literally everything out of the bag, and took batteries out of dive lights. He inspected each light, showed special interest in the 360 degree tank lights which I turned on for him.
He stated that batteries must be removed from all devices but only removed the battery from one of the 3 dive torches, he didn't mention it again as he inspected my camera including my video lights.
He was polite, respectful and apologetic about the process, nothing was denied and there was no suggestion to check any of the items.
People have been told that the reg is a weapon..I don't know why people carry them on anyway; they are almost indestructible, and are easily packed securely in checked baggage.
Checked luggage may get lost, misdirected, or smaller expensive items can be stolen. I don't want a dive trip ruined because my gear didn't make it with me and I'm rather attached to it. I've got my AI transmitters on my 1st stage between my two reg sets and my wife that's almost $600 right there. I'd never be under the weight requirements if I packed all the stuff I mentioned above in my checked bags, I'd incur heavy international baggage fees. Thankfully my heavy backpack (probably close to 40 lbs) has never been subject to weighing at check in. And who wants to go to the trouble of replacing gear that doesn't need to ever be out of your sight in the first place?
The only thing that gets checked is my BCD, wetsuit and fins, and believe me I've considered wearing them onto the plane. But the fins could be problematic when they use the steps rather than a jetway and the BCD may confuse a security agent into thinking I'm a suicide bomber.