Most of our passages are just my wife and myself. The three on and three off works well for us. I also feel that 8 hours, especially at night on a short handed boat, is way too long. We keep fixed watches, since I like the 0300 to 0600 and have difficulty sleeping as early as 1800. On the other hand my wife can sleep 1800 to 2100. If we have guests (only people we know well and who have sailed offshore before), we alternate our shifts with theirs. If it is a husband and wife--as 90% of the time, we let them decide if they want to both be on watch together or stand alone. Usually we stand part of the first watch with them, to be sure that everything is gong OK. They also know who is to be awoken if necessary--and have instructions to wake the skipper if there is any question. (yes I have been awoken by the rising mood mistaken for a ship bearing down on us). There are five stages of sleep--the first two (transitional and light both last relatively short peroids (15 to 30 minutes), but comprise a majority of the sleep time. Stage 3 and four are deeper and last at least 30 to 40 minutes in each cycle. To have meaningful sleep, one needs several hours. This is why we like 3 hours of off watch-this allows some stage 3 and 4 sleep. Only two hours is too short. Also during the day, we will both take a nap--often to 4 hours, while the other is on watch. We do consider watch keeping a full time job. We don't have the watch keeper cook or do oil changes. We do read or listen to music when on watch--but every 5 minutes at least look at the Radar, look around the horizon (usually stick a head outside). Another issue is the health of an offshore crew. Sleep deprivation can lead to mental problems and we have seen temporary psychosis which had to be treated with sedation for 24 hours. Also the captain must know any physical problems that the crew has. I am aware of several deaths at sea, because a crew member was a diabetic, could not eat and slipped into diabetic or hypoglycemic coma. If I was taking "unknown" crew I would insist on a physician's evaluation of that person for suitablity of the voyage. Ultimately the captain is responsible for the crrew's health. Although seasickness can be an agrivation on a short voyage, it can be a very serious problem on a passage. Bob Austin