Gnomish Submarine
by Karl David Brown from Threshold Magazine issue 31This article proposes a gnome-built submarine, seaplane, and diving suit. There is also a new gnomish sub-race. All of these are given game statistics for 5th Edition D&D.
Submarines have a long history in Mystara. There are rumours of an air-filled dome from the days of Blackmoor at the bottom of the ocean but to date no one has found it and returned. Submarines of some kind must have enabled the construction of this dome, if it really exists. Ancient writings do describe Orchanna's Fabulous Machine, a fully developed submersible possibly of Blackmoorian origin.
In the modern era there has been at least one submersible built in New New Mistraven1 in Alphatia. This vessel intended to emulate the capabilities of Orchanna's Fabulous Machine but perhaps relied too heavily on existing magical items rather than developing mechanical solutions and the vessel fell well short of its stated goal. The undersea boats of Aquas in Alphatia are more successful. The Alphatian vessels are steel with crystal windows and use magic to supply air and movement.
This latest version is a collaboration between the gnomes that in previous generations helped build the Ierendi navy and the flying gnomish city of Serraine. The idea was to provide a portable aeroplane launch platform to enable greater trade and tourism between Ierendi and Serraine. It was made into a submersible as a defence against pirates and to offer tourists views of the beautiful reefs off Ierendi's islands. The submarine itself was constructed in the docks of Filtot on Honor Island by gnomes of The Citadel. The Serraine skygnomes are very secretive about aeroplane technology so building of the seaplane was undertaken at Serraine. The seaplane is stored on the flying island and rendezvouses with the submarine in the inlet of Filtot when the flying city is above. Cruise in the submarine with a mixed crew of sky and sea gnomes then ventures forth.
Image: Gnomish submarine and plane http://pandius.com/sub.png
Caption: Gnomish submarine and plane, hand drawn by Senarch https://www.deviantart.com/senarch/gallery
The 'Island Princess' Supreme-Skyratchet Friendship Submarine
A cooperative effort by the gnomes of Serraine and Filtot has produced a passenger and cargo submarine that can also carry and launch a specially designed biplane. The submarine is a long steel tube with a thick layer of water- and barnacle-repellent paint to prevent rust. At the front is a large thick glass dome for the helm just below the brightly painted wooden figurehead of a gnome-mermaid. Smaller portholes dot the sides of the tube to give passengers a view of the sea. Four adjustable fins allow the helm to steer the ship. A rear poop deck is a hanger for a seaplane which is launched off a rail by an oversized crossbow. Above this is a turret with a ballista and another large porthole to allow the gunner to aim. At the rear of the ship is a large propeller. This is rotated via gears and belts by a crankshaft turned by a stone golem. The crankshaft also powers fans that waft air from a small portal to the Elemental Plane of Air bounded by a 1-ft-diameter brass ring etched with arcane glyphs. This air is also piped to bladders in the buoyancy tanks used to rise or sink the vessel.
Entry to the submarine is by an antechamber sealed at both ends with heavy doors set in rubber gaskets. Air can be pumped in or let out to enable personnel or rubbish to be ejected while submerged. The same principle on a smaller scale is used for the submarine's two latrines, one for crew and the other for passengers. The interior of the submarine is brightly lit by heat-free continual flames. The fully equipped galley also has a small bar, though on duty crew are not served alcohol. Comfortable leather-upholstered hardwood furniture is found throughout passenger areas. Passengers and the captain have individual cabins with comfortable beds big enough to sleep a human. The rest of the crew 'hot bunk' in gnome-sized hammocks in the cargo hold. The helm instrument panel includes a clock, compass, fuel gauge, speed gauge, depth gauge, spirit level, plumb bob, and checklists.
The crew is assumed to be all gnomes and crew areas are scaled accordingly. There are three watches each with a helm, golem wrangler, steward, and gunner. The day watch helm is the captain. Additionally, when Serraine is near enough to send the seaplane there is one gnomish seaplane pilot.
There are cabins for 20 medium-sized passengers and a spacious cargo hold that has on occasion housed not only the off-duty crew but also an additional 20 'cattle-class' passengers. Usually though, the hold contains the ship's provisions of food and fresh water and the passengers' luggage.
Size: Gargantuan (290 ft long and has a beam of 25 ft)
Speed: Swim only 15 ft. (1.5 mph).
Range: Like most ships with a full crew of three watches the vessel can operate continuously until the food and freshwater stores are exhausted. How long that is depends on exactly what is packed in the cargo hold and how many passengers are aboard.
AC: 15
Hit Dice: 14d20
Hit Points: 175
Special Defences: Immune to psychic and poison damage.
Golem: The golem wrangler can eject the golem, a process taking 2 rounds. At the end of the wrangler's second turn the stone golem exits the craft and promptly sinks to the bottom where it can perform tasks or fight bottom-dwelling denizens of the deep. This prevents horizontal movement of the submarine until the golem is retrieved or a creature with strength 22 or higher takes on the exhausting work of turning the crank. The vessel can still use its buoyancy tanks to sink or rise and may still drift in strong currents.
Attacks:
Gunner Attack: Ballista with mechanical reload all on a swivel. Hit Dmg 2d10 piercing damage; Reload is automatic after 1 round due to a clockwork mechanism. A ballista's ammunition hopper holds 10 bolts. Refilling the hopper and rewinding the loading mechanism takes one hour but can be part of a short rest. Range 120/480. See also underwater combat in the Player's Handbook. As a giant crossbow this weapon does not suffer disadvantages underwater.
Ram: The submarine is not designed to ram but if you insist... adjust attack roll by -2. Hit 5d8 bludgeoning damage to the target and the submarine. If the target is Large or smaller they are knocked prone.
Maintenance Proficiencies: gnomish 'skyhooks', tinker's tools, alchemist's supplies, brewer's supplies, calligrapher's supplies, carpenter's tools, cook's utensils, glassblower's tools, herbalism kit for casting rubber, jeweller's tools for fine mechanisms, leather worker's tools, mason's tools to repair the stone golem, navigator's tools to calibrate navigational aid as well as aiming mechanisms for the ballista, painter's supplies, smith's tools, and woodcarver's tools.
Purchase Price: Valued at 80,122 gp but as state secret of Ierendi is not for sale.
Power: Very Rare.
Smurfri-Lodestar F3G Island Clipper
An enclosed-cabin twin-propeller biplane, the Island Clipper is a modified version of the F3F Cloud Clipper. Large floats were added above the landing wheels enabling this aeroplane to set down on the water. The fuselage is reinforced with a steel rod in the floor that ends in a hook. This enables the craft to withstand the forces of being fired into the air by the Island Princess's rapid launch system, a massive ballista. The wings can also fold back to enable the aeroplane to fit in the hanger under the submarine's poop deck. This eleven-seater aircraft typically holds the pilot and ten passengers. Alternatively, 8 VIP passengers can be carried and a tour guide and steward serving prepared food and drink. The Island Clipper is simply painted bright orange for visibility. The cabin is enclosed to ensure passenger comfort. The aeroplane is powered by a magic fuel tank delivering power to a pair of wooden propellers. Other features include leather safety harnesses on hard-wearing leather upholstered seats. The instrument panel includes a compass, fuel gauge, airspeed gauge, spirit level, and plumb bob for the pilot.
The Island Clipper was created by the Smurfri and Lodestar clans under contract to the Serraine City Council as part of a trade agreement with the Kingdom of Ierendi. The clans receive a percentage of all tariffs generated by the City Council's operation of the aeroplane.
Size: Huge (31 ft. long).
Speed: 50 ft (5 mph) on flat level ground. Swim speed on water surface 40 ft. Flight speed 100 ft (10 mph) with 5 or less people aboard, 90 ft (9 mph) with 6 or more people aboard.
Range: 3 hours' flight time using a fire-spell-powered type B magical 'fuel tank'.
AC: 14 when flying (Dexterity 12). If not flying AC 13.
Hit Dice: 24d12
Hit Points: 192
Special Defences: Immune to psychic and poison damage. However the crew and passengers probably are not.
Rapid launch: In two rounds the Sea Princess's hangar door can be opened by a member of the ship's crew, then the aeroplane is launched 120 feet into the air by a gunner operating the enormous crossbow. Finally, the spring-loaded wings sweep forward into their flight position. Passengers and crew not seated during this procedure sustain 5d6 'falling' damage as they are flung backwards by inertia to the back of the cabin.
Attacks:
Pilot attacks: Two synchronised spike guns (see below) granting a multiattack. Missile weapon attack for 1d8 piercing damage. The ammunition is iron spikes of the kind commonly used by adventurers. The hopper holds 20 of these and a mechanism loads the next spike a round after the weapon shoots. Therefore the weapon has the load property. The hopper filled with ammunition weighs 10 lbs. Range 130/520. Ammunition costs 6 sp for 20 spikes. Refilling the hopper and resetting the loading system takes one hour but can be part of a short rest.
Passengers: A locked cabinet stores 16 hand-held light crossbows each with a case of bolts that passengers can shoot out of the windows in the event of an attack.
Ramming: Adjust attack roll by -2. Hit causes 6d4 bludgeoning and receives equal damage itself. A target huge-sized or bigger reduces the aeroplane's flight speed to zero and it falls. Flight speed stays zero until all damage to the aeroplane is repaired. If the ram reduces the aeroplane's hit points to zero then the fuel tank explodes as described in 'Crash and Burn'.
Maintenance Proficiencies: skyhooks, tinker's tools, smith's tools, carpenter's tools, weaver's tools, woodcarver's tools, alchemist's supplies, painter's supplies, leather worker's tools, navigator's tools, and glassblower's tools.
Purchase Price: 7,277 gp, but never for sale.
Power: Very Rare.
Magic Fuel Tanks
A secret of Serraine and not manufactured anywhere else. These vessels not only hold magical energy, they turn a shaft that protrudes from one end. This shaft is then attached to belts and gears to power the aeroplane. If they are fuel tanks what is the fuel? When turned off the tanks absorb potent fire magic before the magical fire manifests. They cannot absorb this energy while running and require the spellcaster to be touching the engine. Any spell of spell level 3 or above that normally does fire damage can be used. Each point of damage restores 2 minutes of flight time, therefore 30 points will fill an empty Model A tank and 90 points will fill an empty Model B tank. Roll the damage, do not use an average. If a tank is overfilled the remaining damage explodes in a ball of fire with a 20-foot radius centred on the front of the aeroplane. The excess damage is inflicted to the aeroplane and to all within that radius. Creatures can make a DC15 Dexterity save to receive half this amount of fire damage.
Crash and burn
If a crash or collision reduces an aircraft to zero hit points then the forces involved rupture the magical engine. For every 2 minutes of fuel left in the tank (round up) 1 point of fire damage is done to all within a 20-ft. radius sphere on a failed save and half as much damage on a successful one. The save DC is 15.
Landing and Take-off
Unless launched by the Island Princess's gigantic crossbow, take-off requires 2,500 feet of flat level ground or calm water. Landing requires the same distance. Less than that and a crash occurs. Treat this as 'Crashing Damage' below half of the aeroplane's airspeed if the runway is less than 1,250 ft or at the vehicle's land speed (usually 50) if the runway is more than 1,250 ft. As with all crashes if the impact reduces hit points to zero then see 'Crash and Burn'. Full rules for aeroplane movement and combat are part of the 5E edition conversion of Top Ballista2.
Image: Gnome in diving suit http://pandius.com/gnome3.png
Caption: Gnome in diving suit, hand drawn by Senarch https://www.deviantart.com/senarch/gallery
Mark II Ierendi Diving Suit
Designed as a budget alternative to magical breathing and swimming aids. No magic is used in the design. The Mark II is a sealed waterproof suit of rubberised canvas with a bronze mask with glass goggles that enables clear underwater vision. Additional bronze pieces counter buoyancy. A pair of 'duck shoes' can be worn to enable fast swimming. Breathing is by a 30-foot hose connected to a submarine or a buoy at the surface. Where a buoy is used pulling on the buoy closes valves within and pressure aids in forcing fresh air into the breathing mask. An rarely used alternate system has a bladder of air attached to the diver's back. Only three Mark II Diving suits were made by the eccentric gnome Cutterpin Ballast and all are aboard the Island Princess.
Size: Small (to fit a gnome, halfling, or similar species).
Speed: Swim speed 25 when wearing the 'duck shoes'. Land speed in flippers is halved (round up to nearest 5 ft.
Range: If attached to the submarine or if at 30 ft or less depth so the buoy can reach the surface then breathing time is indefinite. Using the air bladder, or the air in the hose after pulling down the buoy, you can breathe for 4 minutes before feeling the air getting 'stuffy'. Trained gnomish divers head for the submarine or the surface at this point. After 5 minutes nausea and dizziness begin, giving you disadvantage on all checks and attacks. After 6 minutes breathing from the bladder you are immediately reduced to zero hit points. Death saves usually follow.
AC: 9. The suit is clumsy making your AC worse and you cannot apply a positive dexterity modifier to AC while wearing the suit.
Hit Dice: 3d6
Hit Points: 17. If the hose is targeted it is AC9 and accounts for 4 hit points of the suit's 17. A cut hose negates breathing but not the swim speed. On a hit you can take the damage yourself or from the suit's hit points. This is often a good way to avoid poison damage from venomous fangs, poisoned blades, etc. However, psychic damage always affects the wearer, never the suit. If the suit reaches zero hit points you cannot breathe underwater and lose the swim speed.
Special Defenses: Immune to psychic and poison damage. The wearer gains no special protection from psychic damage.
Attacks:
Usual attacks of the wearer: Using the underwater combat rules in the Player's Handbook.
Ramming: Melee attack: On a charge and body slam with the attack roll adjusted by -2. Hit: you do 1d4 bludgeoning and receive equal damage to the suit or the wearer. If the target is smaller than the wearer on a hit the target is knocked prone.
Maintenance Proficiencies: tinker's tools, cobbler's tools, weaver's tools, smith's tools. Requires daily maintenance.
Purchase Price: 2 gp 4 sp. The typical price people are willing to pay make this a losing proposition. The suits for the submarine were heavily subsidised by the Kingdom. All three of the Mark II suits manufactured are aboard the Island Princess. Five Mark I suits were manufactured and these were theoretically destroyed. However, some might be found on the black market. Mark I suits are identical to Mark II's except they only have 5 hit points (and 2 hit point hose). A single human-sized Mark Ia demonstration suit was manufactured for the King of Ierendi. This suit is stored unused in the Royal Armory in the Citadel on Honor Island (valued at 19 gp, 4d8 hit dice, 7 hit points with a 3 hit point hose otherwise as above). If players track down Cutterpin Ballast in the Citadel on Honor Island and convince her to make a suit she will demand 4 gp for a Small Mark II suit or 19 gp for a Mark I Medium suit. She does not have a design for a Medium Mark II suit prepared.
Power: Uncommon.
Repairing and Maintaining Machines
Machines don't heal but can be repaired as part of a long rest by spending one hit die per maintaining gnome up to the maximum hit dice of the machine. A machine can also be repaired during a short rest but only one hit die may be spent regardless of the number of gnomes working. Each member of the repair team must have the mending cantrip OR one of the listed maintenance proficiencies (with appropriate tools).
Hit dice are restored by maintaining as part of a long rest but without rolling any hit die and spending 1% of the machine's purchase price on spare parts. In some instances, the DM may rule that spare parts can be scavenged, e.g. wood for a beached ship on a jungle island. On long expeditions spare parts might be brought along. Each lot of spare parts is two sizes smaller than the machine they repair (minimum tiny) and weighs as much as twice their gp value.
If a machine ever reaches zero hit points it is destroyed and cannot be repaired.
Some machines are labelled 'Requires Daily Maintenance' and these require someone proficient in one of the maintenance tool proficiencies listed for the machine and who has the Tinker trait to maintain the machine as part of that person's long rest. A person can only maintain one such item at a time. Failure to maintain makes the contraption stop working until it is maintained again. This maintenance cannot occur during a long rest when repairs are being made.
Skyhooks Tool Proficiency
A collection of tools for assembling machines. Treated as a type of artisan's tools proficiency here. For cultural reasons only gnomes have access to these at the start of the campaign. Through roleplay a character of another species might be able to arrange to learn to use these tools during play.
Skyhook Set
See Top Ballista page 39: 200 gp, 10 lbs
I like to think that among the assorted tools are three actual 'skyhooks' which look something like gaff hooks but when placed levitate in the air until moved by a creature or the hook's weight limit is exceeded. The weight limit is 10 lbs per hook. The skyhooks are Common magic items worth 50 gp each.
Sea Gnomes
Most gnomes live inland in gentle hilly regions or among dwarves. However, along the coasts of Ierendi and Alphatia gnomes live by the sea. A small proportion of these that spend most of their time out on the water are sea gnomes. Like the sky gnomes of Serraine they are descended from ground gnomes that in a few generations have adapted to a new environment. It is suspected that rapid evolution to new environments is a weakly magical trait bestowed by Garal Glitterlode, the Immortal creator of the gnomes. Among the sea gnomes some of the adaptations include pupils that contract underwater to provide clear vision, an instinctive smooth swimming motion, larger hands and feet, and the ability to hold their breath. Furthermore, generations on the sea have given sea gnomes a deep cultural knowledge of the sea in all its moods.
However, they remain gnomes with their curiosity and love of mechanisms. Sea gnomes were among those in Alphatia, and later Ierendi, who designed, constructed, and crewed submarines.
Being a curious folk at home on the water, sea gnomes often take to sailing to far off places and getting into all kinds of adventures.
Sea Gnome traits
You gain all the core traits of gnomes in the PHB then instead of one of the two 'subraces' in the PHB you have the following traits:
Artificer's Lore. As per the PHB rock gnome.
Tinker. As per the PHB rock gnome.
Swim Speed. You have a swimming speed of 20 feet and therefore also see and act underwater like a native.
Hold Breath. You can hold your breath for 15 minutes.
Seaborn. You have advantage on saves to avoid damage from liquid water-based phenomena and magic including waves, tsunamis, etc.
You also have resistance to damage from water-based attacks but not cold.
Improved Darkvision. Your darkvision range is 90 feet.
Sea Sense. Advantage on nature checks when underwater or on the surface of the sea to determine depth, direction, and distance travelled, and if waves, whirlpools, currents, and weather are natural phenomena. You can predict weather while at sea or within 1 mile of the seacoast.
Sources: Top Ballista (PC2), Book of Wondrous Inventions (AC11), The Kingdom of Ierendi (GAZ4), Dawn of the Empires: Thyatis and Alphatia, and speculations at The Piazza forum (https://www.thepiazza.org.uk/bb/viewtopic.php?p=320490#p320490).
Inspiration from the drawings of Leonardo Da Vinci, the Moken people of Thailand, and the Royal navy's HMS M2 submarine of 1918 - see wikipedia: https://en.wikipedia.org/wiki/HMS_M2_(1918).
1In AC 11 The Book of Wondrous Inventions (https://www.drivethrurpg.com/product/16978/AC11-The-Book-of-Wondrous-Inventions-Basic) New Mistraven blew up 'some time ago' and so a new one was built, see also in the Vaults Official details about Metropolitan Alphatia by LoZompatore http://pandius.com/metroalp.html and the original article by the author Gnome Submarine http://pandius.com/gnomesub.html
2Top Ballista, 5E Player's Guide by the author can be downloaded for free in the Vaults of Pandius http://pandius.com/5eTopBallistaPlayerFormatted.pdf