I would not go to sea in a 27' sailboat without paper charts. Yes, laptop-based charts (especially NOAA raster charts...RNCs) are great, and I have used them on my own boat for many years.
HOWEVER, you can't depend on a laptop
working 100% in an offshore
situation, especially on a smallish boat where electric
power is at a premium (and laptops eat a lot of power) and where water
damage possibilities are heightened.
So....... download the NOAA raster charts by all means, put them on your laptop
, use an appropriate charting program, and learn how they work.
BUT, acquire and carry on board PAPER CHARTS as well. The Chartkit charts are convenient and appropriate. Whatever they cost, they're worth it.