Since the "spoofing" (intentional degradation) of the signal has been lifted, it has made a huge difference in the accuracy and precision of the $100 handheld machines. You can reliably expect to get readings of +/- 20 meters(and better). This can usually get you back to the mouth of the jetties with little problem.
Most of my experience has been with the Garmin 12XL (
http://www.garmin.com/products/gps12xl/), would definitely reccomend it. A friend just bought a 12CX (
http://www.garmin.com/products/gps12cx/), the color screen is nice, and the extended battery life is nifty as well.
Lots of different brands out there.
Good luck.
TR