The easiest way to find out is to apply for an ICC and see if the course you did is accepted.
If not I would suggest doing a Powerboat Level 2 direct assessment, which definitely qualifies you for the ICC.
If your not familiar with the terms used in the maritime industry, padding out your CV will likely be spotted! Probably worth doing the actual course.
In any case the ICC (International Certificate of Competence) is what you are after, without knowing what was involved in your Zodiac course I...
The RYA PB2 course is often priced up to 300GBP, it is an internationally recognised certificate and you can also then apply for an International Certificate of Competence which is useful for operating small leisure craft in various jurisdictions.
Sekura is quite right, volunteering for a...
My guess would be the surrounding politics, such as Austria's position and the handful of years where we and the Yanks thought we were getting good intel when really Ivan knew what we were up to.
Potential embarrassment for all concerned.