Garmin Etrex is a great little "basic" gps unit, simple to operate, waterproof & inexpensive. It will hold 500 waypoints and will leave a track line so you can find your way back. As for the time in Japan option, sorry, all gps units will do that.
These units sell for 115 bucks at numerous places, probably find 1 for around 100 at the Boat Show or Sportsman's shows.
IMHO, quality control at Garmin is superior to Magellan, especially in the lower end units.