The REC emergency course, by virtue of being a 16 hour assessed course provided through a body which can demonstrate due diligence, covering environmental issues, casualty packaging and transport and with a paediatric element satisifies and in many cases exceeds the requirements of all outdoor national governing body (NGB) awards that I'm aware of.
The BCU aquatic first aid course does not technically satisfy the criteria for non-paddlesport qualifications (because BCU lifeguards does not yet have the quality assurance systems in place to demonstrate due dilligence). In practice nobody seems to bother about this.
The REC advanced course in addition to ticking all the boxes that the REC emergency course does, is also an acceptable advanced first aid qualification for rescue 3 SRT/WRT instructors. It requires people to arrive on the course at a good REC emergency level.
In the tabs above I've summarised the first aid requirements of all the different NGBs with links to the appropriate parts their websites
