Waverunner Mk.IIa (Solo campaign ready)

This submarine is clearly useful for those who don't have friends available to play Barotrauma with, but I also highly recommend giving it a try if you've primarily played multiplayer. It is a unique experience to challenge Barotrauma, deep within the void in total solitude, hours away from the nearest living human, with nothing and no one to depend on but your own self-sufficiency.

99.9% of credit goes to Blart for the original Waverunner Mk.II, https://steamcommunity.com/sharedfiles/filedetails/?id=2221541968, of which this is merely a light modification.

The Waverunner Mk.II is a small, minimalistic sub designed by Relic Runner Blart. Because of its small size, the Waverunner is extremely agile, and is able to outrun most of the threats Europa has to offer. It features a condensed version of Captain Eric's Arc Reactor System, two coilguns, one railgun, an artifact-compatible airlock system, a relatively massive engine, and a lot of spunk.

The IIa variant is designed to be operated by a single intrepid captain, optionally with a helper player or bot. Like the base variant, this submarine is more than capable of completing the campaign.

Strengths:

• Simple and efficient to operate by a single crewmember.
• Easy to manually operate silently. Turn off the reactor, keep the throttle on low, and don't accelerate past ~20.
• Straightforward maintenance, especially once you've gotten some progress into your skills.
• Faster than a bat out of hell. With engines on high, you can go from zero to 60+ in about five seconds. In a sufficiently open area nothing will be able to catch you if you need to get away.

Weaknesses:

• Ballast balance is extremely sensitive, due to the small overall volume. Even filling the airlock will cause the sub to start sinking.
• The airlock entrance is outside the gun firing arcs, and it'll frequently be breached by wildlife.
• Single-compartment design means that even minor breaches will lead to major flooding and immediate sinking. You need to be well-prepared for rapid damage control, and understand how to use autopilot to keep yourself alive when you're not at the navigation console because you're busy stabbing mudraptors and sealing breaches in the hold.
• Running the reactor efficiently requires thorium fuel rods. You'll want to buy any that you come across, and it'll be a major early game drain on your finances until you understand how to manage power usage optimally.

The sub comes with only the barest minimum of equipment. You will want to take inventory before leaving on your first mission, and strongly consider spending your starting capital on some extra equipment. Wearing a diving suit at all times while aboard is recommended.

Major changes against base Mk.II variant:

• Greatly expanded storage. Nobody'll be around to help you organize items, so the storage space crunch has been alleviated to reduce un-fun time spent dragging items around. You can also carry a meaningful amount of raw materials for long trips into the depths of Europa without excessive toolbox management. A crate shelf has been added to make it harder to lose mission cargo in the event of a major hull breach.
• The coilgun periscope has been moved to the command room, to make one-man steering and gunning easier. The railgun periscope and loader have been moved out to cargo. Lack of shell storage racks is intentional.
• The engine's peak output has been reduced by 25% to make it more manageable, and a toggleable power limiter caps output to 30% so that using manual steering for ordinary maneuvering is no longer a life-or-death proposition, while preserving the ability to make a quick getaway when you need it.
• The oxygen generator can be toggled to conserve battery power when you leave for a dive.

Minor changes:

• The display screen next to the reactor now shows remaining battery charge in kWh.
• The sub is now waypointed for an AI helper, who is best used manning the guns and maintaining equipment. The reactor area intentionally lacks waypoints to discourage bots from pulling your thorium fuel rods out of the reactor and throwing off the automatic reactor control system, though sometimes they'll manage to get in there anyway.
• A status panel has been attached to the navigation console, to make finding stray leaks less irritating.
• One set of extra thorium fuel rods is provided to make the early game progress a bit faster.
• The neutral ballast level has been tweaked to make holding the sub at a standstill more straightforward.
• The interior is slightly better lit when lights are deactivated.
• Two extra fire extinguishers in locations that are less likely to already be on fire when you need the extinguisher.

Automated Reactor Control System:

• Push the left button to activate. Requires automatic control on the reactor to be off, and four thorium fuel rods loaded in the reactor.
• Push the right button to enable direct reactor power to ship systems, which can be useful if your battery is damaged and that mudraptor a few feet below in the cargo compartment is too enthusiastic for you to risk an electrical burn right now.
• The reactor can generally safely be powered off at any time to conserve fuel. For maximum safety, 1) deactivate automatic control, 2) power off the reactor, and 3) set the battery's charge rate to 0%.
• For optimal efficiency, you should turn off the reactor and use battery power once in a while.
• See https://steamcommunity.com/sharedfiles/filedetails/?id=2080129857 for more details.

A depth charge system would make gameplay more interesting, but also probably make things too easy.