Got my helm qualification in the Army many years ago and that was just Basic Sailing. At that time I found out all the information in what was then DCI's. The course was taken at the APT School (N) outside York. Hope this is of help.
Get your arrse on a course up in Kiel. You can get all the RYA quals that are gettable in the system. Oh yes, you can get them all in Gosport as well, but I'd rather spend my time sailing along the coast of Denmark and Sweden than France any day!
What branch/corp you in? they should have a yacht club online which should have details. asa site http://www.sailarmy.co.uk/ may give more info, so will ad trg publications your trg wing has. 14 Sigs in Wales offer courses so do HQ Land. dont bother with your level 1, it'll do nothing for you, go straight for your 2.
If you look at the HQ ATG (A) web site under army net www.armynet.mod.uk the DCI (course dates) is listed and JSP419 (The Course Oulines). Gosport is the lead centre but as listed above you can find couse most places.