I want to buy a new GPS chartplotter for my boat, and am trying to decide the most suitable cartography before deciding on a specific make/model. I am looking for best bathymetric detail. Don`t need harbours, etc.
I boat/fish the eastern end of Lake Ontario mostly on the Canadian side. The paper chart I normally use is Canadian Chart # 2064 (Kingston to False Ducks).....
Most chartplotters will run you at least $500, plus $200 or so for charts. The plotters in this price range will have a 5" screen, which is not that big when you are used to a large paper chart.
Based on your cruising area, and you essentially use a single chart, I would suggest an inexpensive GPS that will show you latlon, leave breadcrumb as you go, and can store maybe 500 or 1000 waypoints and 10 routes, which will run you around $100-$150. Then continue to use your paper maps to plot your location. The CHS charts are usually around $20 a sheet, and #2064 was just updated and printed last month. So for about $120, you are set. Then, every few years, it will cost you another $20 for an updated chart.
If what you really want is a GPS with chart of a fairly large area, like all of Canada, a Lowrance unit is a good choice. They use Navionics charts, which in my opinion is one of the best marine chart providers. If you want a larger screen, with future expansion to include other sensors, then Raymarine or Garmin are all good choices.