The SVX-17M Slug Mariner is a single-crew minisub. While it is needed to go beneath the surface, this sub can be abandoned while underwater and re-entered.
The Slug Mariner is equipped with two 10mm caliber Vulcan cannons. However, water resistance decreases the range of the Vulcans, so it is loaded with incendiary ammunition that sink when shot so it would hit enemies below. It also fires powerful torpedoes that create a large shockwave upon impact. This is extremely useful against larger underwater enemies from Rebel submarines to hostile aquatic creatures.
In Other Games
Although the Slug Mariner is present in promotional art, it is unused in this game alongside scrapped underwater routes. Most of the necessary animations are present but with a brighter color scheme.
The Slug Mariner appears in the game's Treasure Hunt mode, with Marco piloting it. Aside from that, it isn't playable nor obtainable as a unit.
The Slug Mariner is present as a purchasable skin for the Wave Rider vehicle. Uniquely, its metallic tail fin flaps around like it's an actual fish.
The Slug Mariner moves at the surface of the water. The player submerges the sub by holding down the screen/button and emerges it by letting go causing the sub to jump in an arc. The Slug Mariner jumps higher depending how deep it was beforehand.
- 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.