Archipelago fairway along the northern coast of the Gulf of Finland from Hanko to Ahvenkoski. 1790?.

Map without title information depicting the northern coast of the Gulf of Finland from Ahvenkoski (Abborsfors) to Hanko (Hangö). - Stockholm : Swedish Admiralty, 1790?. - Copper engraving printed in two parts. Map area size 440×1094 mm. - The archipelago fairway Hanko–Barösund–Porkkala–Helsinki–Villinki–Loviisa, with its branches, is precisely marked so that on both sides of the line depicting the fairway there are lines depicting the width of the fairway. The reimars are marked. The depth figures expressed in feet are only found in the inner archipelago. – Literature: DR: "As it also lacks a grid and title, it seems to be a proof of an incomplete map possibly made for military purposes... For coastal navigation it is superior to Nordenakar's chart. It... may be produced for use during the 1808 war but was never completed after the war". A comparison of the map with the Nordenankar and Klint maps shows that it is much more accurate than the Nordenankar map, but less accurate than the Klint map. The Hanko forts and the Porkkala lighthouse are missing, which suggests to the time around 1790. There are two lighthouses in Orrengrund and its name is in plural. A customs office is marked in Barsösund. Depths are in feet – not in fathoms as usual. The archipelago fairway is depicted on the Klint chart and has there even more branches than here. At least some of the description of the open sea is clearly based on the Nordenankar chart.