Traditional watch systems, including the "Modified Swedish" are good, but can leave a crew very tired, as off-watch times may shift all over the day and night. This can dramatically disturb sleep cycles.
After the 2000 and 2002 Pacific Cup, many members of our crew, particularly including yours truly, slept for 17 hours straight after hitting land. I set about to develop a watch system that kept wake/sleep cycles as constant as possible while still giving everybody a break from the dreaded 2 am watch.
The attached watch schedule is actually based on a 26-hour day, with 13 different watch periods. It's a little complex to write down, but, for a crew of six, it provides an excellent amount of sleep time off watch while shifting the watch periods as little as possible. Note: this only is set up for a six-person crew, with two on and four off (standby). While I believe the core concept can be adapted for other crews, I have not successfully done so.
The spreadsheet lets you print out your own version. The watches overlap, so there is continuity or overlap between watch-standers. We have found it most useful to alternate the more experienced with less experienced sailors so you have one of each on watch at all times.
|AA||Alex||1. Enter the initials of the crew at left. Alternate stronger with weaker to complement skills|
|bb||Bill||2. There are thirteen watch periods of 3 or 4 hours each|
|CC||Carl||3. Watch periods overlap. Each crew serves with two others|
|dd||Donna||4. Wake and sleep times change by only one or two hours per day|
|EE||Eric||5. Off-watch time is 6 to 8 hours for maximum fatigue reduction|