lame1 is right on the $$. Be careful what you wish for.
If I ever do another cruise I will not even bring my laptop. It doesn't really work like hotels shops where you can work in the room and have the report done when you leave. Taking the time to write the report on the ship just wrecks the entire value of the experience, IMHO. I would sightsee in every port and set aside 3 days from the moment I got home to complete the report.
For my last cruise, I kept detailed notes in my phone and emailed them to myself, then worked from that. The report took me 25 hours to complete and and I'm relatively quick with that style of reporting. I got about 20% of the report finished on the ship. It was a 5-night cruise, so I would have had to set aside 5 hours per day to write it up while onboard. I don't think I had 5 free hours on any day aboard the ship! Between all of the meals, housekeeping, shore excursions, turndown, spa visits and such, you are on the go from the moment you board.