Coastal maps and charts of the 18th century Finnish Gulf: navigation, archipelago warfare and maritime infrastructure

What do coastal maps and charts tell about navigation, archipelago warfare, wrecks and maritime infrastructure of the 18th century Finnish Gulf (Gulf)? A closer look at the maps reveals a hidden maritime infrastructure: passages, vantage points, pilot homes, secret bases for enemy (Russian) fleets at the Porkkala peninsula, land routes (draget) for hauling the galleys, beacons, small fortified islands with water reservoirs, natural harbours, windsawmills, fortresses and bold utopian-like plans for archipelago strongholds (Nordenbergs Fagerö at the Sipoo coast) etc. As an example of coastal mapping with interesting details of this kind can be mentioned e.g. the works of Jonas Hahn.

The Finnish archipelago was a unique environment, which gave birth to unique warfare: the archipelago war with oared vessels, galleys. Actually, the Gulf was the last place where Mediterranean style galleys were used. This ancient vessel disappeared not until at the beginning of 19th century. The archipelago war required coastal mapping and strongholds.

The founding of fortress Sveaborg 1748 as a base of the galley fleet was a major turning point for the charting of the Gulf. Extensive charting began in pace with the construction works of Sveaborg.  As a matter of fact, it was the archipelago fleet, which gathered information e.g. sounding data via Admiralty to map-makers like Hahn, Nils Strömcrona and Gustav af Klint. The archipelago passage from Stockholm to Sveaborg became the most important passage of the realm. It is not surprising that the first geodetic survey in Finland after Maupertuis was carried out in the 1740s and 1750s at this passage by Johan Gadolin. The chain ended, not by chance, to Sveaborg. Due to the leading role of Sveaborgs commandant Augustin  Ehrensvärd  the headquarters of the coastal mapping was in Sveaborg. Ehrensvärd had a map collection of his own and this map-oriented officer understood well the profound meaning of maps in war.

Besides the archipelago passage, the southern passage in the middle of the Gulf to St Petersburg was in commercial sense one of the busiest in Europe. The Dutch merchant ships, like famous Vrouw Maria, with their luxury cargoes dominated the passage until the end of the century.  There were several shipwrecks at the Gulf per year. The Scheeren, as the Dutch called the Finnish archipelago, was a troublesome place for foreign ships, even though most of the captains were specialized to the rough conditions of the rocky waters. The role of the diving and salvaging companies of the coastal towns had a dual role, they salvaged the wrecks but also profited from these. A shipwreck was a gift from heaven to the coastal population. A lighthouse was built on Rönnskär island at the notorious Porkkala peninsula at late as 1800. One can ask, why not earlier?

These themes will be presented by Mikko Huhtamies at ICHC Conference in Helsinki, 30 June to 5 July 2013.