economical / reliable gps for marine navigation??

Hopefully someone can help me resolve me ongoing issue with hunting for the right gps unit, i'm pretty dumb on the subject, since i rarely travel far enough via water ways to need assistance in finding my way back to port. However , i recently purchased a new vessel and i have spent a great deal of time making it my " home on the water" even tho it's only a 19 ft bowrider. never the less, i live on the eastern shores of lake ontario and have a nasty channel to navigate to reach the harbor then to the lake , If the water is slightly choppy it becomes rather difficult to locate the channel, and navigating it during limited visibility or at night is near impossible. Since i am among the working class , as u can tell it's only a small craft..lol, i do not have need for an expensive gps unit, nor could i afford it with the price of gas anyway. Anyhow , there is a great deal of fun things to do on the water around here, and i am looking for an inexpensive gps unit capable of tracking my course thru the 4 miles of channel required to reach the lake, and then be able to return under limited or no visibility, say , after watchin fireworks at a local harbor fest. Some thing simple, inexpensive , and capable of getting me home safely. Any suggestions any one? I'm not necessarily looking to punch in way points every 5 seconds, and follow them in a decending order to return home, something more along the lines of a handheld that can track or record my passage from port , so i can follow it almost perfectly back. Thanks to anyone who can help.

 

One more thing, west marine has on sale for 69$ a handheld cobra gps100 , i have read mixed reviews not to mention i'm not sure if this is the unit that would be capable of meeting my needs , and is price indicative of quality in this instance?