CycleCat
Contributor
It's funny, I was going to bring up the PADI wheel, which I used to use back in the day. I actually liked it, although I'm sure they've long since relegated it to the trash heap. I'd bet someone could find one on one of the auction sites, it might be fun for the OP to play around with if he wants to work with dive tables.
I saw one on eBay a few weeks ago.... nearly bought it!
I'm a science nerd at heart and need to have some understanding of what is going on in spite of following the DC.