If you are planning on cruising in an open 16' dinghy, which is to say as bare-bones, risky, self-sufficient, basic and primitive as can be (like Robinson Crusoe and Gilligan's Island) why are you even asking about navigating? Why not go as basic and primitive as can be? Maybe a lodestone? A chip of
wood? Aw heck--go all out and find an astrolabe! I think a compass is too advanced. I dunno--do I seem cynical? You're not going to run aground. I'd be more concerned about being seen--take a
radar reflector and a high intensity light,
EPIRB, survival suit....(no room for a liferaft). Did Thoreau set out to Walden and take a smithy's forge? Did Thor Heyerdahl take radios and other
electronics? If you are setting out on such a bold and self-imposed difficult adventure, why even worry about taking the most modern and advanced deices? You need room for
food, water and
weather gear">foul
weather gear. Who has room or eight for batteries or solar collectors? Now, if you were setting out for example, in even a 27' sailboat, I might add a few things--depth sounder, AWI and vane, compass,
charts etc etc...but if you were to bike across country would you be taking a tv? A
generator? No, but maybe in an RV.. It can be done--not for me but I wish you a bon voyage!