Every time I navigate to a different page I have to reselect the language. Is there a way to get around this?
The question doesn't really make sense, functionally.
If you always want to translate to the same language, maybe you should look at providing translation links instead. Assuming you're using a CMS of some kind, just go to the main Google Translate page, give it some URL/language combination and submit. You'll end up at something like this:
...which is a link translating
http://example.com from English to Japanese.
Then, in your CMS template, replace the value of the
&u query parameter with the URL of the current page, URL-encoded.