Fiz, if you are going to navigate anywhere really accurate charts are the way to go.
You can never have anything better than an accurate chart.
An up to date paper chart is the best, with corrections marked, but no one likes handling them.
Navionics charts are great, not the out and out best, but they do a really good job.
I note that my Navman GPS plotter is 14 years old, that means it has old charts as well.
I have noticed in the past 10 years a lot of large pleasure boats are using computer systems on their boat for navigation
and engine monitoring. They install a PC, large touch screens on the dash all connected to the Sounder, Radar, GPS and any other sensor they elect to use - example night vision sensors.
Yacht racing has been using laptop and tablet based systems for navigation, measuring and monitoring for at least 20 years.
I have always believed that having separate units are safer than having them all in one system.
A few years ago, my son and I was travelling back to Auckland from Fitzroy at about 10 pm and 20 miles from A Bouy we had one of the boat circuits crash lost all lights, Sounder, GPS and Autopilot.
Fortunately the other circuit was okay and we had the VHF and Radar to enable a safe entry without lights.
So my Furuno Sounder, Radar, Navman GPS and Raymarine Autopilot are all separate units and will remain so in the future.
You have made two wrong statements twice -
"Most boats using it will have a Sonar to alarm them of other vessels/objects in close vacinity."
"And if navigating by navionics in the dark a person is asking for trouble. Thats what Sonar is for. So you dont run some people over, or worse get run over by a container ship."
Sonar will never prevent a collision with a container ship or a 12' tinny out fishing in the dark..
Sonar measures only what is under the boat. Radar identifies what is around your boat.
Only AIS and Radar can prevent that happening but you need to be monitoring the radar screen and keeping watch.
Note Radar showed up Astrolabe Reef to the crew of the Rena, but they were not monitoring the screen - crash.
AIS is not installed on many pleasure boats so is not appropriate in this discussion.
I do a lot of cruising at night and it is very safe, so long as all boats are correctly lit.
And I still carry a sextant, learnt how to use one in 1978 and I still enjoy the magic of deriving a position line from the sun or stars.