I’ve been involved with the National Cipher Challenge for several years, first as a participant and then (when I went off to uni) as an elf. I’ll be keeping an eye on the forum for Harry (and letting him know, if necessary, who’s been naughty or nice).
I’m also a baby mathematician (about to start a PhD), so I can do my best to answer questions about maths and studying it (particularly at Southampton).
Another elf reporting for duty too. Hope you are ready for your first, or another fun year breaking ciphers and enjoying a good story. We will try to help as we can, but also remember this is a competition, so it will not all be easy and the help may not come as quickly or as clearly as you want!
I believe (I don’t use one, as you can see!) that you can have one gravatar per email address, and many emails associated with one gravatar account. So if you use a different (eg school) email address for your account here, or if you use a service that lets you create aliases (such as gmail’s “+” trick) then you could have one just for this site.
It’s definitely something of a work around and (as I said) I haven’t followed this advice so I have no understanding of the process… But Google is your friend in this situation!