The site is more advanced than you might expect. It is possible to chose between several types of map's over the same area, also including
satellite and areal photos (witch has much better resolution and quality than
google satellite photos) - on top of any of these
charts you can then overlay almost any type of overlay data, including maritime
ENC data such as buoys, lighthouses, fairways, subsea installations etc.
It is possible to create geo referenced jpg 's with the overlay you choose with a resolution down to 1:625 and a"print size" up to A2. You an download this file direct and for free - The file from the website can easily be converted to a kap file for
opencpn. Se example attached
screen shoot showing a areal
photo displayed in
opencpn as a .kap , made from a geo referenced jpg from the website