For the 1st time on the 5218-218/A, 1996, pre-Vendôme era.
Rumor or reality the story says it was only ever produced for a total of 5 pieces. This watch is one regular 44mm PVD Luminor case with a black dial and small seconds. Its movement was the regular UT 6497. The second rumor says that the 5 possible pieces were assembled once the Officine Panerai were sold to the Richemont group.
The name Black Seal has been used on a few Radiomir models and on the Pam 191 compass too.