LOL
Interestingly I was introduced to a 'roma'? by another crew from my club (we entered 5 this year!).
The idea is its a grid you set up for your map marked up for long/lat intervals such that you can very very quickly with a piece of acetate locate a long/lat - all waypoints in the competition are given in long/lat so it makes it very easy...Ill definitely be making one up!