I saw this on Facebook, do their SSI Nitrox course for $99 instead of $249. They're based in Sydney, and this course doesn't include any actual dives (not required for this certification).
PREREQUISITES
The minimum age to participate is 12 years old (a parent's or guardian's consent is required for participants under 18 years old.)
Be certified as an SSI Open Water Diver / SSI Junior Open Water Diver, or hold an equivalent certification from another recognised certification agency.
Are you sure there is no face to face competent for this? ProDive appear to require a face to face after the online course is done?
I'm not sure. This is definitely a theory only course with online course material. I don't know if you need you need to turn up for a written test or anything like that.
The Nitrox exam is written. Plus there's a practical element on showing you how to test tanks using the oxygen tester and labelling the tanks.
I'd also recommend doing a deeper dive on Nitrox whilst under supervision the 1st time (not technically required). Nitrox carries a higher risk of oxtox and everyone feels the effects differently, so best to do it the 1st time under supervision.
There is no way you can achieve Nitrox certification without actually doing dives on Nitrox.
I am an SSI certified nitrox diver. From memory it was 2 nitrox dives when I qualified less than 3 years ago.
I googled it, SSI says the dives are optional, https://info.divessi.com/en/enriched-air-nitrox-176.html (Facts section on the right)
This looks to be an SSI course not a Padi Course
Doubt it matters if you have each others qualification though
I just realised that it because it's theory only (no practical work required) you should be able to do it from any location, not just Sydney.