Enemy ships in the harbour of Gibraltar have been in the sight of the Royal Italian Navy since September 1940. After several attacks by “Gamma” frogmen and SLC units, ideas to build a secret base of the Decima MAS were realized in the second half of the year 1942. Convoy ships for the United States were beginning to arrive in quantity. The numbers of potential targets at anchor in the Bay of Algeciras were growing almost daily.

Earlier in 1942, a base for the Decima MAS “Gamma” frogmen was established in the Villa Carmela near La Linea from where several missions were carried out against British merchant ships (see page 126-131 / chapter II.I). During the months of shaping Villa Carmela into an advanced base, the idea for a bigger and much more effective operation had taken form in the mind of Licio Visintini, one of the SLC pilots of the mission B.G.4 in September 1941 (see page 374-381 / chapter II.III) which was carried out from the submarine Scirè.

Before the new base was ready for action, each attack at Gibraltar had required a long submarine voyage, air and land transportation of the attack-teams, the shipping of supplies and weapons, arrangements for rendezvous, an approach by submarine, and finally the task of smuggling the survivors back to Italy thru neutral Spanish territory.

Licio Visintini’s idea became real with turning the anchored ship Olterra inside the pier of Algeciras into a secret base for SLC missions. Visintini and further technical specialists replaced the original crew of the Olterra. An assembly workshop for the SLC devices (which arrived in sections, declared as spare parts for the damaged ship) was established in the hull. A portside cabin of the Olterra became the observation post with an excellent view of Gibraltar harbour. Finally, a folding door on the port side bow (see coffee table shot of page 386-387 /chapter II.III) became the exit door for the SLC units below waterline to reach their targets – and to return back into the hull of the Olterra. After months of intensive work in total secrecy, the inconspicious ship Olterra was turned into a Trojan Horse – “il cavallo di Troia” – and six men were ready for action with their SLC devices.

The Olterra was starting point of the following SLC missions against enemy ships in the bay of Algeciras / Gibraltar harbour: B.G.5 (7/8 December 1942), B.G.6 (7/8 May 1943) and  B.G.7 (3/4 August 1943). Our book “The References” 1930’s-1940’s features two Ref. 3646 watches which were used during these missions.

The Ref. 3646 / Type A “Radiomir Panerai” watch of Ernesto Notari is featured in chapter II.I (page 58-91 / see coffee table shot on the left) – more on this watch and its history can be found here. The Ref. 3646 / Type C “Radiomir Panerai” watch of Licio Visintini is featured in chapter II.III (page 350-367) – more on this watch and the history behind can be found here. The new “The References” books can be ordered only in our bookstore.

Enjoy reading!
[Ralf Ehlers & Volker Wiegmann]