The 1851 Census is of no interest to me, as my Naval ancestor was not at the hospital for the 1851 Census.
However, I was able to make some use of it for some Naval General Service Medal recipients' research. Although I have now deleted the files that I had, there was some supplemental info that I was able to gather.
In the 1841 Census, there is a useful annotation against the name of the in-Pensioners in the infirmary, to indicate if they were a Sailor or a Marine. In the 1851 Census, it is in the inverse sense, whereby those men in the infirmary have nothing recorded, whereas the others have S or M against their name. My copying might contain transcription errors. It appears that some errors occurred at source; Peter Moser was not a Marine, for instance.
Key:
S Sailor
M Marine
I Infirmary, therefore nothing recorded
B Blank, nothing recorded