Again, it's some time since I updated this blog, but the wait is, I hope, worth it. PCDB Waypoints now has the ability to display a route on a map, with the waypoints indicated by markers and a line joining them. The zoom level of the map is set to ensure that all points on it are included in the area shown. Where a Waypoint is defined by reference to one or more nearby Marks (i.e. by the distance and bearing from the mark), then at an appropriate zoom level the marks, too, are shown with bearing lines joining them to the appropriate Waypoints.
And, the piece de resistance, grid lines are shown on the map which move around as the map is scrolled, and the grid spacing changes as the map is zoomed.
Here are some screen shots. The map used is the Open Steet Mapping (OSM) default. This covers the entire world, but at varying levels of detail, and there are indications that in some areas the coastline (at least) is not properly mapped. But it's certainly enough to get this project going.
This shows a popular cruising route in North Wales, from Abersoch to the anchorage at Pilot's Cove behind Llanddwynn Island, just outside Caernarvon bar.
After zooming the map in a few times, and touching the icon representing the Waypoint just south of Llanddwynn Island, an InfoWindow pops up showing the details of this Waypoint and the two Marks that define its position. One is a South Cardinal mark at 308.5 degrees, and the other the Llanddwynn Island lighthouse immediately North of the Waypoint.