A smart boater doesn't give up the charts. You still have to know where
you are, and where you are going. I always lay out my course on the
paper chart and track it on paper too. In a boat GPS is just another
tool and should never be used as the only source of navigation.
I always have in my mind, course, speed, and time, with GPS it's from
waypoint to waypoint, just a change of terms. I always know what the
heading should be from one waypoint to another and have caught many
errors because I did know.
The biggest mistake new boaters make is not learning basic navigation
skills. I boat in the western end of Lake Erie, there are to many reefs,
and islands that will not let you just look up a waypoint to where you
want to go and enter it in a GPS and launch off on the trip. More than
once a season a boat will end up on the beach or on a reef, many time
killing one or more on board. Why, because they entered the waypoint
they wanted and took off at night, and sure enough that island was right
on their straight line course. They would have known that was the case
if they would have charted it first, before leaving.
The other problem is that the units can fail half way thru the trip and
at night or in even a heavy haze, you'd have no clue as to where you
were if you didn't back the GPS up with the tried and true methods. The
only difference today with GPS you don't have to be quite as careful
ploting and tracking.
The only thing I totally rely on my GPS for is "time to go", I have to
go thru a draw bridge to get to my dock, it opens on the half hour, so I
set my speed to be on time. The problem if the GPS screws up, I sit for
a while waiting for the bridge to open, no big deal.
So if you're smart you will still have and use the paper charts.