I bought the 334gps and have just now put it in the boat. I have not tried it on the lake yet. I did a lot of asking about the pros and cons of the internal verses the external antenna. From what I gathered the internal is as good except do not let the unit lay flat on its back because it will then loose the signal. I was informed that the pros tried to use it that way. I hope to try the GPS out soon and will post how it performed. I will of course try to get it to not work by placing it in different positions.

Nick