Mariupol is an expansion for "Battles of XXI Century" ("Bitwy XXI Wieku") system - you get board, tables and counters and two scenarios but the core game is needed, because you need the rule book and help counters. This is not a stand alone game.
War of Ships is the stand alone game, with board, counters, rules, tables and three scenarios.
The game was published in issue 40 of Taktyka i Strategia (Tactics and Strategy) magazine in both Polish and English editions.
Scenarios are included for the following games:
Kursk 1943 (2 scenarios)
Battles of XXI Century (4 scenarios, including two for Mariupol and two for core game)
Battles of the II WW (two scenarios and 2 for Mokra 1939)
Crecy (two scenarios)
Borodino 1812 (one scenario)
ASL Starter Kits 1-3 (two scenarios)