I agree with Jim... The Fortrex or Forerunner for OUR uses... Because they are small... The Forerunner is good... However, I did find more of its features applying for running whereas the Foretrex has a few more features that were attractive for sailing... But that's all a preference thing...
Also, the 201 Foretrex OR Forerunners are rechargeable whereas the 101 uses two AAA batteries... This is the ONLY difference between the 201 and 101... At first I thought that I wanted the 201... But then after I thought about it for a while (how long you ask!?

), I decided that I wanted the option of being able to put in new batteries, and not having to be somewhere to recharge it... If you are backpacking, it's nice to only have to bring extra batteries... The batteries on my 101 last a long time...
Also, they are water resistant... So, I took off the stock wristband and bought a small rafting water proof pouch from Kirkhams for 10 bucks. Put the wristband through the slot ON the pouch and slid the GPS into that... Works like a charm and keeps it relatively dry. I can put it around my wrist, the mast, or the boom... Also, there is a special cable that believe it or not is difficult to get your hands on. It is for downloading data onto your computer. Whichever, one you get may not come with that cable... however, I know of a special place to get it... Email me if you get one.