John Thomas Serres, Point de Roquilon, France. Captain M. K. Barritt. Eyes of the Admiralty: J T Serres, An Artist in the Channel Fleet, 1799-1800. London: National Maritime Museum, 2014. Image: United Kingdom Hydrographic Office. Don't think you'll find it on the UKHO website however, this appears to be a working website of great complexity for contemporary documents, maps, charts and shipping publications.
About the time I was young and tooling around on a little sailboat in Nanaimo Harbour, I found a book of drawings of the BC coast done by an artist on Captain Vancouver's ship. They looked much like Serres' paintings (above) – navigation charts, meant to point out signal points, rocks bays, harbours and dangers. These and Vancouver's drawings, which I've never been able to find again, delineated land, not from land itself but from an opposing position on the water. The land is the objective other.
It is interesting, from our map-dominated representations of land today, that in the eighteenth century elevations were as necessary as reckoning by the sun: they are visual one-to-one maps without translation to a plan. Of course they eventually had charts, but Vancouver was in uncharted territory: a drawing or a painting bypassed translation, gave the context and the scale of the coast, especially if it was potentially hostile.
From the water, the land-bound built environment is very small – a toytown between the sky, the mountains and the sea, all huge. Even approaching a city such as Vancouver by ferry, its complex urbanity is itself but a pale cluster, not very tall, almost irrelevant. From the middle of the strait one can see that the Island is the top of a mountain range, that the strait is full of small islands, that there are dozens of boats from tugs to freighters, container ships to barges: daily life on a terrain that remains mysterious to those on land.