An "autorating" system uses peer ratings to award marks to individual students in team assignments. This is a simple tool intended to help educators streamline the calculation process of autorated marks, available for download at https://bitbucket.org/liantze/autorating-calculator. You will need a Java Runtime Environment (> 1.6) to run it.
This template contains all information I would personally log after a dive. Feel free to use and /or modify it to create your own custom dive log book.
If you are not familiar with LaTeX and would like to make minor changes, drop me a comment on my blog at http://texblog.org/2015/07/22/diy-scuba-diving-log-book/