As of the writing of this post, there are three particular answers to What would an out-of-water submarine (for water-breathing mer-people) look like? which have raised some eyebrows, mine included. The question essentially asks for a land-based version of a military submarine for an aquatic species:

My mermen & women are at WWII era warfare and interested in their version of 'underwater,' meaning they want out-of-sea vehicles (sorry, there is no antonym to submarine) to fight over land similar to our attempts to occupy the seas with submarines.

The first two of these three answers - including the most upvoted answer of all, with 64 net votes (+66/-2) - are essentially just pictures of a fish tank on wheels, with little explanation or supplementary material that relate to the question. The third one is better, but could use a lot more explanation. Here's the full text of the 64-vote answer:

A fish-tank

enter image description here

A one has been built already: https://youtu.be/YbNmL6hSNKw

If I saw that answer just posted to the question, I would consider it a joke and might delete it. However, I didn't see it when it was just posted, and it now has a score of 64. Now, I'm not saying that highly-voted answers shouldn't be deleted, but none of the mods would, I think, be comfortable taking unilateral action on a post this well-received.

What do people think about these three answers? Are they valid answers, which should be left alone? Are they jokes, which should be downvoted and/or deleted? Is there a middle ground somewhere?

Meta discussion and reviewing in the queues seem to indicate that the community supports deletion. As such, all three posts have been deleted.

  • $\begingroup$ Do any of these answers explain how the fish will control the vehicles? Or does the question really allow for "container that you need someone else to push you around in for your military operations"? $\endgroup$ Feb 28, 2017 at 21:51
  • 2
    $\begingroup$ @MonicaCellio In general, there's no other information given in the answers, and the question does mention some other things an answer would need to address (there are no air-breathing humans, the vehicles should be for military use, etc.). These answers just ignore all of that. $\endgroup$
    – HDE 226868 Mod
    Feb 28, 2017 at 21:53
  • $\begingroup$ no air-breathing humans doesn't actually affect the craft in any meaningful way. Not more than lack of mermaids affects our submarine designs. $\endgroup$
    – Mołot
    Feb 28, 2017 at 21:56
  • $\begingroup$ @Mołot The second one requires a human to move, it seems. But none give any details about locomotion, so really, we have no reason to think a lack of humans wouldn't be problematic. The point is, these are not good answers, and I'm arguing that they don't count as answers at all. $\endgroup$
    – HDE 226868 Mod
    Feb 28, 2017 at 21:57
  • $\begingroup$ @HDE226868 Please see a comment under my answer. If this fish bowl on wheels is indeed a vehicle controlled by the fish from inside, then it is an answer. Except, maybe, for "military" part, but not all military vehicles are armed anyway and question did not specify any specific requirements. $\endgroup$
    – Mołot
    Feb 28, 2017 at 21:59
  • $\begingroup$ @Mołot It's irrelevant, because the answer doesn't explain that. Look, I'm not saying the idea is invalid, but I'm saying that posting a picture and a link without any explanation should not be an answer in any sense of the word. This is the kind of thing that is often deleted on sight as a joke. The only thing here is that one of them has been upvoted quite a lot. $\endgroup$
    – HDE 226868 Mod
    Feb 28, 2017 at 22:01
  • $\begingroup$ @HDE226868 Well, then it should be flagged as VLQ and deleted as link only. But the Powers (aka SE developers and team) decided that this path should not apply to heavily upvoted answers (by blocking VLQ flag). Probably they had their reasons, and this site is their business, after all. So if the problem is that it is link-only, then it was decision of SE team that under current circumstances path to deletion should not be available. Only you moderators know when you are allowed and expected to overrule such decisions. $\endgroup$
    – Mołot
    Feb 28, 2017 at 22:04
  • $\begingroup$ I agree with @kingledion's answer on this one, the only real difference between the two highest voted answers is that one is in text and the other one is a picture, but they are essentially the exact same answer. To be honest, while neither are great answers, the picture one is almost the better one of the two as it shows a real, working, machine and could be improved with a short description of how it works; the second answer does have a (very) brief outline of how it ought to work, which are not thoroughly considered (the oxygenation won't work as described), and a somewhat sarcastic tone. $\endgroup$
    – Mrkvička
    Mar 1, 2017 at 7:21

3 Answers 3


The question is fine, the answer is not

I disagree with @Molot's answer. There are plenty of good, thorough answers to the question, and it is completely possible to cover the bases just like with any other "good" post.

Popular questions tend to get lots of attention, and that often results in some relatively bad answers, but that doesn't mean the questions are bad.

While the answer "a fish tank on wheels" may have been so widely accepted because it seems like the obvious choice, it is not fit for the site.

  • We dislike link-only answers. Links are not always active, meaning the answers may not be around forever, and it can be hard to tell if they're credible or safe. In this case, the link is helpful, but the answer should put in more effort to explain how the link is relevant or what its consequences are for the OP's world.
  • It doesn't fit the scenario presented by the question.
    • The OP is looking for World War II - era tech, while this tank was created in 2014, and uses computation, analysis, navigation. and sensors that are not appropriate for the given time period.
    • The OP wants something that is likely pressurized: humans are most comfortable with diving equipment at the depths the creatures in question can reach, so they may want the same when they come to the surface. A normal fish tank does not meet this need.
    • The OP likely wants something that can be fueled underwater, which may require a different process, and something which can be entered without needing a human to scoop you out. The answer does not address specific concerns with swapping water for air in this scenario.
    • In general, the answer requires the reader to bridge a lot of gaps in order to adapt it to the question. It presents an idea, but does not attempt to apply it to the circumstances given.

This answer may seem clever and interesting, but it does not meet site standards. I recommend deletion.

  • $\begingroup$ Note that path to deletion as link only is not avaliable. As far as I remember this was intentional network wide decision, and that would mean that even if we don't like it, Stack Exchange does. $\endgroup$
    – Mołot
    Feb 28, 2017 at 23:21
  • 1
    $\begingroup$ +1 anyway because your answer generally makes sense. $\endgroup$
    – Mołot
    Feb 28, 2017 at 23:22
  • $\begingroup$ If the community shows clear support for deleting something that the tools don't allow regular users to delete, moderators can step in. But we're not going to do it on our own. $\endgroup$ Mar 1, 2017 at 1:31
  • $\begingroup$ @MonicaCellio Link basis aside, it does not answer the question, which seems to be more of a problem $\endgroup$
    – Zxyrra
    Mar 1, 2017 at 2:01
  • $\begingroup$ There are some posts which honestly tries to answer the question, but only one or two are really good. The question is "what would it look like (using WWII tech)", no more; this open up for a lot of speculation and opinion, but can be answered subjectively with reasoning and engineering know-how (which are near the extra premises you post). As most answers only very briefly describe why it would look the way they say, the picture ones are bad solely because there is a risk that the picture gets deleted; as long as it does not, then it's no less of an answer than most of the others. $\endgroup$
    – Mrkvička
    Mar 1, 2017 at 8:25
  • 1
    $\begingroup$ I seriously considered editing the question to include one of the tanks-on-wheels images because the comedy was fun and it would forestall further jokes. $\endgroup$
    – SRM
    Mar 2, 2017 at 3:20

I have another doubt, that is:

If the fish bowl on wheels is an answer, was it a good question?

This one does answer the question. It is a vehicle for water breathing creature to move on land. It answers the question that was asked in one of the best possible ways, that is by providing real life example, and it does not contradict anything posted in the question.

Note: Question asked was:

What would a water-filled "landmarine" look like?

Emphasis mine. So details about controlling it may be considered tangential or even off topic to the question. When it comes to look, what's a better answer than a photo? But, as noted, this one indeed is controlled by the fish - and that makes it a vehicle all right.

So I believe that if there is a problem, it is not exactly with the answer.

  • 3
    $\begingroup$ I've seen a video of this in action, the machine actually does move in the direction that the fish swims. Pretty cool, even if the fish has no idea what's going on... $\endgroup$
    – user10945
    Feb 28, 2017 at 21:54
  • 1
    $\begingroup$ I disagree, see my answer to this post. It is not an actual answer to the question, so yes, it is still a good question. $\endgroup$
    – Zxyrra
    Feb 28, 2017 at 23:15

A picture is worth 1000 words

The next two highest rated answers, after the picture of a fish tank, included the quotes,

...these supermarines would not need any fancy mechanisms to keep the water sealed. Just a simple box filled with water would suffice. They wouldn't even need to periodically refill with oxygen. Just having some elongated tubes coming out from the top letting the air desolve into the water would work. You could even open the top of the supermarine every once and a while.


A fish tank on wheels. That would be the basic design.

This picture answer just said the same thing as those other answers.

Now none of those answers are great, but if all the most highly rated answers are bad, then the problem must be with the question.

At this point, I think the ship has sailed on closing the question, though.


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