In an urban fantasy type world, how exactly would public transit work for merfolk?

Situation A: The merfolk are living in a big cross-species city that also has humanoids. For purposes of this question, I'm assuming they have specialized buses. How exactly would these buses work, and what would they look like?

Situation B: These merfolk live in the midway point of the ocean. Not the shallow coral reefs, but not the lightless abyss either. What could they use for their public transit, keeping in mind that they don't really have the ability to use things such as wheels and electricity. The bus would also span several 'levels' as there are no particular streets.

EDIT: The shallow merfolk can avoid water for about a week before drying out, so that isn't an issue. They are based off of dolphins, being able to breathe out of water and being able to hold their breath for 2 hours, though I am considering making it longer. They have no way of getting legs and currently, I have no real plans to put them in wheelchairs, though it is a possibility.

The city either has canals beside the sidewalks or tubes underneath the pathways, though I am leaning towards the former. The public transit needs to be able to get them to the merfolk-oriented areas and the public areas (such as city hall and a multitude of stores).

I'm assuming the bus could drop them off in a canal/tube entrance by the stops.

  • $\begingroup$ What kind of merfolk? Do they suffocate without water, or just slowly dehydrate? Or can they stay out of water for an extended period and thus could move around in wheelchairs? $\endgroup$ Sep 17, 2018 at 23:55
  • $\begingroup$ It would depend on how your city looks and how it has been designed to accommodate merfolk already. If they have to use the footpaths like normal humans, will they dry out? does their tail change into feet? Or do they already have pathways they can swim along with currents, etc etc. You need to tell us more about your merfolk and the actual city design. $\endgroup$
    – Shadowzee
    Sep 17, 2018 at 23:55
  • $\begingroup$ They're a shallow variant that I based off of dolphins and other sea-dwelling mammals. They can safely stay completely out of water for a week, so that isn't an issue. They also breathe oxygen and can hold their breath for about two hours underwater. However, they are so much more comfortable underwater and they have no way of getting legs. I am considering special wheelchair designs for them, but that's a topic for another question. $\endgroup$ Sep 17, 2018 at 23:58
  • $\begingroup$ @Shadowzee i haven't decided between canals beside the sidewalks or tubes underneath, but i'm leaning towards the former. i'll try and edit my post to clarify $\endgroup$ Sep 17, 2018 at 23:58
  • $\begingroup$ Where do you want them to go? Between water and water separated by land? Between land and land? What would they be using to get around on land between public transportation trips and would it come with them? $\endgroup$ Sep 18, 2018 at 0:00

3 Answers 3


If you have canals in and around your city for your aquatic cities, I'm picturing something along the lines of large "Sea Scooters" like that used by human divers. They travel along predetermined routes, and are covered in handy holds that the merfolk can use to hitch a ride. They could be piloted, remote controlled, or autonomous. These could also work in ocean-based settlements.

For fast travel where there are no convenient canals, you could install a series of water slides for easy travel between different levels. For long flat stretches, water jets could be placed at intervals to give a needed speed boost.


For a city like New York or Tokyo, the solution would be to repurpose the subway tunnels. Simply flood them with water (they will naturally flood if left unattended long enough) and the merpeople can swim comfortably to and from work.

Naturally, a system of tubes filled with still water will eventually become stagnant and nasty, being a health hazard for both the merpeople and the population on the surface, so the system will be attended by a maintenance staff who will ensure the tubes have clean water pumped in and oxygenated, while "dirty" water is flushed from the system.

This also provides the "public transit" part of the system, merpeople should be willing to pay to use the system since the currents induced in the tunnels will allow them to move much more rapidly and with less effort. Obviously there will be tubes going in each direction (or the flow is reversed between morning and evening rush hour), and building stations will be different from conventional subway practice.


You could have feeder tubes. The feeder tubes are filled with water and open into watertight compartments in specialised buses or trains. For trains, you could have a regular train with the last couple of carriages being water filled for merpeople. The tubes connect to the bus or carriage, the passengers swim through and the door of both the tube and the public transport close.

If you have multi level buses then bus stops would need to drop down in the road so that normal passengers could get on with wheelchairs and the like on the upper deck of the bus while tubes underground connect with the lower deck of the bus which is water filled. Water filled transport seems the easiest way to get the merfolk on and off. You'd want your water deck on the bottom for a couple of reasons. If it leaked you'd not want the other passengers to get wet. That amount of water is heavy and would create a potential tipping hazard for the bus if on top.


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