Alaskan Sea-Duction, when we started cruising the Inside Passage I was armed with only a Raymarine E120. I quickly found this to less than desirable and needed more information.
I quickly purchase Coastal Explorer, suggest from a dock mate, for my laptop, Waggoner, Best Anchorage of the Inside Passage, Ports and Passage tide book and South Coast of BC, North Coast of BC, and Southeast Alaska. I have spent many hour read/purchasing cruising materials. Here is a great article to read. cruisingnw.com/tides-currents-and-rapids-in-the-inside-passage/.
Oh yeah, I bought paper charts that can take me past Cape Caution from the Second Wave. Unfortunately Second Wave close their doors this year.
After my first trip in 2010 I bought from the Canadian Fisheries and Oceans some digital charts to download to my laptop.
Canadian Hydrographic Service.
With CE I can spend my time in the comfort of my home/boat charting/planning our route, determine departure time to make passage crossing at slack, mileage to waypoint and much more.
An Internet connection is not need for planning. As stated, when you have an internet connection and start up CE, the program will auto update. Also with the internet you can view photos of most anchorages. Below is an example.
Good luck in your quest and have a safe New Year.