As only three of the major factions got subs in MI, I made custom subs for the other three majors who did not get any:
Name: Poseidon
Cost: 14
Faction: English
Segments: 3
Cargo: 4
Movement: S+S
Cannons: 2L-3L-4L
Ability: Submarine. Once per turn, reroll any die roll made for this ship; you must use the second die roll result.
Flavor Text: Following successful experiments with submersible technology, the Royal Navy has developed a new class of ship that will further help them rule the waves.
Name: Resurgam
Cost: 13
Faction: English
Segments: 2
Cargo: 3
Movement: L
Cannons: 3L-3S
Ability: Submarine. Once per turn, one crew or ship within S of this ship cannot use its ability that turn.
Flavor Text: Resurgam was designed with the express purpose of disrupting the enemy’s line of battle undetected.
(loosely based on https://en.wikipedia.org/wiki/Resurgam)
Name: Peral
Cost: 9
Faction: Spanish
Segments: 3
Cargo: 3
Movement: S
Cannons: 2L-4S-3S
Ability: Submarine. This ship gets +S to her base move if she has all her segments.
Flavor Text: Named for her designer, Peral is the Spanish Navy’s most advanced ship yet.
(loosely based on https://en.wikipedia.org/wiki/Spanish_submarine_Peral)
Name: Ictineo
Cost: 9
Faction: Spanish
Segments: 2
Cargo: 4
Movement: L
Cannons: 3S-4S
Ability: Submarine. If this ship has an Explorer crew, she gets +1 cargo.
Flavor Text: An ingenious design, Ictineo was created to help divers preform their duties in better safety.
(loosely based on https://en.wikipedia.org/wiki/Ict%C3%ADneo_I & https://en.wikipedia.org/wiki/Ict%C3%ADneo_II)
Name: Plongeur
Cost: 12
Faction: French
Segments: 3
Cargo: 4
Movement: S+S
Cannons: 3S-4S-4S
Ability: Submarine. This ship gets +2 to her ramming rolls.
Flavor Text: After impressive reports of Nemo’s submarines came back from the Mysterious Islands, French naval engineers were charged with building a vessel capable of similar feats. ‘Diver’ was the result.
(loosely based on https://en.wikipedia.org/wiki/French_submarine_Plongeur)
Name: Gymnote
Cost: 11
Segments: 2
Faction: French
Cargo: 2
Movement: L
Cannons: 3S-3S
Ability: Submarine. This ship has a 4S cannon that can be fired while she is submerged; it cannot be fired when she is surfaced.
Flavor Text: Gymnote was built to serve as a testbed for an experimental new kind of weapon.
(loosely based on https://en.wikipedia.org/wiki/French_submarine_Gymnote_(Q1))