The red pointer marks the site of suspected Russian submarine and/or diver activity in mid October 2014. The close proximity to Stockholm may indicate this is part of a agent drop-off or pick-up activity. Or it maybe connected to Russian electronic monitoring of nearby naval exercises, monitoring Stockholm's own telecommunications grid or tapping an undersea cable.
The many rocks and islets in Swedish waters mean complex and dangerous undersea obstructions and currents for any submarine crew unfamiliar with the conditions.
A Russian Kilo Class submarine - at up to 2,350 tons surfaced probably too large to operate safely in the restricted littorals off Stockholm. Russia's more advanced Lada class submarine(s) are likely to be equally large.
The much smaller Piranha ("Losos") class mini submarine or similar, at 220 tons surfaced, is better suited to closed waters - although more susceptible to currents.
---I think it very likely Sweden and NATO would early on had a clear idea of what type of Russian submarine(s) or divers-frogmen (if any) were involved in this latest embarrassment. Active sonar on many platforms and many other types of sensor modes would have effectively "shaped" the Russian underwater activity. Also the many technical characteristics of the Russian emergency transmissions would have pointed to the type of Russian sub or diver modes involved.
It is more a Swedish-Russian diplomatic matter that Sweden has not divulged full details. Many of the details will be authorised-leaked in time - maybe years.
The suspected Russian submarine (or divers) that making a distress call in Swedish waters may be a Russian Piranha mini special forces submarine, Triton-NN or other mini submarine. Swimming divers in trouble?
The close proximity to Stockholm may indicate:
- this is part of a agent drop-off or pick-up activity or
- maybe connected to Russian electronic monitoring of nearby naval exercises, of Stockholm's own telecommunications grid or monitoring an undersea cable.
Less likely are full sized submarines being directly involved rather than acting as mother-ships, launch points for a diver-propulsion vehicle:
- a Russian Kilo class conventionally propelled submarine somehow involved? or
- a Lada class submarine (B-585 Saint Petersburg) involved. In which case its developing Air Independent Propulsion (AIP) system may have technically malfunctioned? or
- much less likely a nuclear propelled submarine such as the Akula class SSN involved.
Any Kilo, Lada or special forces mini-submarine would likely be from Russia's Baltic Fleet base at the enclave of Kaliningrad Oblast (bordered by the Baltic, Poland in the south and Lithuania in the north) and fairly close to Stockholm.
Suspected Russian submarines have made many embarrassing forays into Swedish waters in the past.
As usual Wikipedia proves invaluable - see entry within http://en.wikipedia.org/wiki/Swedish_submarine_incidents#List_of_major_reported_incidents: