- An old channel goes past the Odensö area. The channel has been used for ages to transport different goods. This important channel has affected also to the fortifications, which have been build to the Odensö area. Much of the responsibility for defending the approaches to Tammisaari has been with the Björnholmen area. This defence however has been boosted by the the gun position 45, & b, which has been fully operational during the war and can be found from the Odensö area. Enemy, which could have get pass the fortifications in Björnholmen, would have come under fire from this gun position, while trying to advance towards Tammisaari.

- The second fully operational gun position in the area has been the structure 46, a & b. This position has been pointed towards the channel, which goes past Sommarö. Additionally the gun position could have fired flanking fire towards enemy, which would have attempted to breakthrough to the mainland. Attacking through the Odensö area, would have offered the shortest route to the mainland for the Russian in the east side of Hanko Cape. This possibility has been thought of in the above fortification map, as the structure 435 and 437, a & b, have been build towards this possible attack direction. At the same time these structures have also protected the channel, which goes past Odensö. The channel is visible in the fortification map. It is marked with a broken line.

- The mined structure 435 seems to have been destroyed completely. In the area to which the structure has been marked, stands now a big summer cottage. There is some sharp edged stones, which have been created during the mining job. The mined structure however cannot be found anymore. The structure 437, a & b, on the other hand is in much better condition, because it contains several different structures.

- There is a lot of structures in the area of Odensö, which have been numbered starting with a number six. There are really no traces from these structures in the area. This is nothing strange, because structures, which have been numbered, starting with a number six, cannot be really found from Harparskog-line. All of these have been planned to be accommodation bunkers/dugout, located behind of the main defensive line. Because the first line positions have not been completed, there really has been no point of starting the construction of other structures located far away from the main line.

- The lookout tower of Bötesberget cannot be seen in the fortification map. It is located within one and a half kilometers east from the structure 655. The lookout tower which is located there is a new one, but during the existence of the Soviet rental area of Hanko, there has been also an lookout tower. During the wartime, the lookout tower has offered a great general view to the left flank of Hanko Front. I warmly recommend climbing to the tower, because it shows clearly the reason why the Russians were disappointed to their rental area. The Finnish forces could observe the rental area very easily.

- We couldn't verify the existence of the structures 446 and 654, because the shores of Bastholmen are so full of summer cottages. It is impossible to anchor to the island so, that you do not disturb the summer residents. It is most likely, that the mined structure 446 can be still found from the island, as it is located inland and most the summer cottages are in the shoreline. It is very unlikely, that there is anything to see from the structure 654, because of its numbering.

- I would be very grateful, if some summer resident of the island could give a permission to anchor to the island. This way the existence of the structures 446 and 654 could be verified and perhaps also documented.

- My own personal notes below are based on the situation in the defensive line, during the years 2005 and 2006.