No direct experience, but there is a good write up of this in both The Voyagers Handbook by Beth Leonard, and Sensible Cruising/The Thoreau Appoach by Don Casey and Lew Hackler. Both are great reads.
We set it for 20 minutes. When it goes off the first thing we do is reset it. Then we flip the radar from standby to scan. Next is a thorough visual of the entire horizon, by now the radar has run a moment and we check it on all the range settings from 16 miles down to 1 mile. After that is several different ranges on the chartplotter checking for AIS targets. Then comes a look at our course. After we're satisfied that all is clear we flip the radar back to standby and resume a vegetative state. By now 6 or 7 minutes have past and the alarm starts the cycle again after only about 13 minutes.
I can fall asleep pretty quickly so this system works for me. I know I'm not getting good REM sleep but I can usually sleep a good 20 to 30 minutes or so out of every hour. So I am getting enough rest and I feel like I'm able to keep a good watch.
Hi....I've sailed many solo miles and often…. when not in a shipping lane…. will sleep during the day watch during the night and always put an alarm on the RADAR, 5 miles out and works just as well at night. Usually my instincts sharpen when at sea solo and I sleep less and for shorter periods.
I have solo sailed up and down the east coast of the US and from the Azores to Lagos Portugal and around the Med. When I am awake I always us a 20 min timer cause even when awake I am cooking, working on projects or relaxing and need to do a scan. During my sleep time if I am not in shipping or boating lanes or fishing net areas I use the radar alert set for 8 miles and sleep. I find that when I am in shipping lanes or inshore I can only go for a max of three days using short sleep systems without ending up sleeping through my alarms and having very rude awakenings with ship noises around me. Not something you want to repeat very often. I will say that in my experience ships have MOST of the time been very aware of my presence and respectful of my course etc. I agree that until I get over tired or sea sick my awareness and instincts are very sharp at sea vis a vis my boat sounds, weather and what is happening around even when sleeping. Pax Steve
I have over 50,000 miles single handed, mostly western Caribbean and Central America. First if you're in shipping lanes you don't sleep. When I'm not in shipping lanes I use a kitchen timer and sleep 15min stand scan 360 reset timer for 15 min. I usually sleep in the day time and stay up at night. I have used a C.A.R.D. ( collision avoidance radar detector) but you would be amazed how many big ships have no operating radar. If fatigue becomes an issue I have hove-to for four hours to get needed rest, When hove-to I display a mast-head strobe. (not entirely legal but it gets captain's attention) When open ocean sailing I sleep in two hour sessions with the VHF turned up loud.
When we took longer passages, like 2-3 days, we tried to find groups of boats to sail with. We always invited solo sailors so that they could get some rest while underway. We would sail within visual range and keep a look-out for them (as well as our own boat) for a spell, usually a regular watch period of 3-4 hours. They could get some uninterrupted rest knowing that someone was keeping a eye out for them. Of course, they have to have a trust-worthy auto pilot and the conditions need to be appropriate, but we did this on a few passages and helped out at least a couple of short-handed sailors!