The two submarines depict on this stamp are sisters and belong to the Ronis class of the navy of Latvia.
RONIS: was built by A.C. de la Loire, Nantes, France for the navy of Latvia.
1925 Keel laid down.
01 July 1926 launched as the RONIS (seal).
Displacement 390 surfaced, 514 ton submerged. Dim. 55.0 x 4.80 x 3.60 draught.
Powered diesel electric by two Sulzer diesels, 1,300hp, and two electro motors 700 hp., twin shafts, speed surfaced 14 knots and submerged 9 knots.
Range by a speed of 14 knots, 1600 mile and submerged by a speed of 4.5 knots, 85 mile.
Armament 1 – 75 mm, 2 – 7.62 MG, 6 – 21 inch torpedo tubes, two bow and 2 x twin external turn-able.
1927 Commissioned.
SPIDOLA: was built by A.C. de la Loire, Nantes, France for the Latvian Navy.
1925 Keel laid down.
06 October 1926 launched as the SPIDOLA (Mermaid).
The other details the same as given by RONIS.
The two boats were coastal submarines built after a French design.
19 August 1940 Latvia was annexed in the Soviet Union and the two submarines were transferred to the Russian Navy not renamed.
The two boats were joining the 3rd Battalion of the 1st Brigade.
22 June 1941 the two boats were at the navy base at Libau (Liepaja) waiting for major repairs at the Tosmare yard, they were before declared unfit for combat service.
In the night of 23/24 June 1941 the RONIS and SPIDOLA were blown up by the Russian crew to avoid capture by the approaching German forces.
In 1942 the two submarines were salvaged by the Germans and scrapped.
Latvia 2011 100lvl sg?, scott? The other two ships are the VIRSAITAS and SKRUNDA.)
Source http://en.wikipedia.org/wiki/Ronis_class_submarine