I have Navionics
and I have used them between Nova Scotia
and Trinidad for a total of 15,000 miles and once you leave the USA and Canada
the accuracy decreases:
Bahamas....not reliable in fine detail; good light navigating only in shallow waters
Islands...mostly accurate but occasional significant error. The Island of Rodondo was off by 400 yds.
South and Central American coasts are much worse...not accurate enough to make night entries. The Spanish waters entry in Curacao
showed me to be in the Hyatt hotel
swimming pool, in Puerto Morelos, Mexico
it was off by 400 yds and in the offshore
islands of Venezuela
accuracy was even worse.
These are not errors by Navionics
but in the original charts. While Explorer data might be more accurate, in the Bahamas, the Explorer charts all carry a 'Navigate at your own risk'