Hi Louisew, when you send Dr Edge your diabetes and diving forms, he emails you back a medical form C -Fitness to Dive with Diabetes form. I've never been refused by any dive shop overseas whether Padi, SSi or Bsac. Like you, I don't dive in UK anymore. I used to email dive shops first to check they're okay with me diving with them, but so long as you have that form from Dr Edge, they are happy. I always take a couple of copies with me. I've noticed some dive shops want the DAN forms also, so I ask my GP to sign that at the same time as completing my forms.
Before each dive, I give the dive leader the diabetes 'talk' as concisely as I can. I explain about exercise, insulin and hypo's. The L-sign with your hand in front of your face is the universal sign for a hypo when diving. I keep a tube of Glucogel (available on prescription or pharmacies) in my Bcd pocket in case of hypos. I show them where that is, how to use it and to do a controlled buoyant lift up to the surface, deploy a dsmb should I do the L- sign (which I've never had to do).
Sadly, I often find dive leaders are too distracted about the dive to take my diabetes seriously enough. That's where the Libre's give you confidence. Some dive leaders however, have been well-briefed by diabetics previously and have been more aware and supportive.
Now I've got my Libre, I've notice how dehydrated you get after a dive particularly in hot climates, which puts my blood sugar up. So I try and drink plenty of water.
There's quite a bit of info on the internet about diving and diabetes. Good luck!