My maternal grandfather joined the RN in 1896 as an acting ERA. He was commissioned in 1903. He was apparently at an establishment/ship numbered 462 in 1919 which is not listed in 1923. The name apparently starts with "Le" or "Li".
His pre-commission papers show him at a name that looks like "Tewairo" in 1903 which has "5a 5" or 1a 5 beside it in the List and No. Columns.
Any anwers out there? Cheers!

It will be LEVEN; the number refers to its position in the Navy List. It was a torpedo boat destroyer.

Tewairo? can't work that out.  If you could copy it, and post it, I can try and work out what it actually says.  

For a photo of Leven, see:
http://www.battleships-cruisers.co.uk/hms_leven.htm

Thank you PhiloNauticus - I was directed to you by an ex-RNZNVR man singing your praise.
I have posted a scan of the name on Flickr. Link here
http://farm3.static.flickr.com/2632/3890410171_b19e1c994a.jpg

Cheers

I have had a look - it is indeed a real scrawl, but I think it is TEMERAIRE.  

This was an old battleship, built in 1876, paid off in 1891. From 1901 she was used as a depot and accomodation ship at Plymouth, and from 1904 as a floating machinery workshop, as part of the 'Indus' training establishment at Plymouth.

Thank you again, that would fit the bill as he is shown as qualifying at the end of that time. Then followed nine months at sea on Sirius and he was commissioned.