The Slug Mariner is an underwater Super Vehicle used by the Regular Army.
The SVX-17M Slug Mariner is a single-crew minisub. It is equipped with two 10mm caliber Vulcan cannons. However, water resistance decreases the range of the Vulcans, so it is loaded with incendiary ammunition, so that when the shots stop and sink they would hit enemies below. Like the Slug Copter though, moving and trying to line up an accurate shot can prove pretty challenging, making it one of the more difficult Slugs to master. It is also fires powerful torpedoes that create a large shockwave upon impact, extremely useful against underwater enemies from Rebel submarines to hostile aquatic creatures. While it is needed to go beneath the surface, this sub can be abandoned while underwater and re-entered.
The beta version of the Slug Mariner appears in Metal Slug X, in an underwater beta stage from Metal Slug 3. Once again it appears in the sprites of the Metal Slug Advance and even has all the necessary animation for being used in the game, but the game didn't/doesn't have any underwater levels.
- The "4" seen on the side of this Slug and the yellow coloration are both a homage to Thunderbird 4 from the classic British TV series Thunderbirds.
- The "4" may also refer to the four main protagonists; Marco, Fio, Eri and Tarma.
- The unused Slug Mariner in Metal Slug Advance has a brighter color scheme than the usual Slug Mariner.
- The Slug Mariner appears in Metal Slug Attack's Treasure Hunt mode, with Marco piloting it. Aside from that, it isn't playable and isn't obtainable as a unit.
|Mechanized||SV-001 (Metal Slug) | SV-001 Type-R | Slug Copter | Slug Flyer | Slug Sub | Astro Slug | Slug Gunner | Slugnoid | LV Armor | Walking Machine | Slug Mariner | Drill Slug | M-15A Bradley | Metal Claw | Forklift | Slug Mobile | Augensterm | Protogunner | Slug Digger | Slug Trolley | Slug Armor | Slug Gigant | Golden Slug | MS-Alice | Ball Slug | Slug Square|
|Animal||SV-Camel | Elephant Slug | Ostrich Slug | Donkey Slug|
|Other||Middle-Son 1986 | Middle-Son 1999 | SV-002 | Borobune Slug | Motorcycle | Parachute Drop | Drop Pack | Regular Army Helicopter | Landseek | PA33-21 Boat | RA-TTT | Rootmars|