As of October 2016 (a year late) the 2015 Royal Navy coin is appearing in circulation. As suspected, it bears the 5th portrait of the Queen, making it distinctly different to the Royal Navy coins that were included in the 2015 sets made available by the Royal Mint. All of the six different 2015 dated £2 coins can be seen here.
The Check Your Change admin is Mr C H Perkins, publisher of numismatic publications in printed and eBook format. Author of "Collectors' Coins - Decimal Issues of the UK" and other books on British coins and related subjects.