I really wanted this feature of being able to capture ships, but how would one even go about implementing this? it would probably need drastic change in mechanics, and so much more. (oh yeah, cool historical balance: If this does get implemented, Kushites should get a bonus of capturing ships,due to Nastasen's historic victory against the egyptians that made him capture lots of ships)

Of course, one soldier on a fishing boat should not be able to capture a large warship. But 10 warriors on a merchant ship, capturing an empty ship (conditionally empty, i.e. without a garrison) with close contact - why not. If, of course, the boat can swim close and stay afloat for some time without being sunk. Very suddenly, one player's unprotected fleet (without a garrison) can be intercepted by an even weaker fleet (but with a large garrison) of another. In my opinion, this would be very interesting and generally corresponds to the historical outline, when ships were captured on board. Note: That’s why I wrote the idea about a two- or three-fold advantage of units in the garrison of a ship going on board, so that it would not be one soldier, but several. And of course, there must be technologies that improve boarding practices. For example, “grinding hooks on ropes”, which could significantly reduce the time required to capture a ship. And vice versa, the technology “high sides” and “military commandant” to reduce the possibility of boarding a ship (increases the time for interception) even if there is no garrison. And if there is a garrison on the ship, these technologies make it very difficult or almost impossible (as with towers). Moreover, “high sides” are only for wood. And the “military commandant” technology is only for metal.   ..... But these are all dreams... dreams.   However, maybe the developers will really like it and do it? 

Once upon a time, the idea of capturing a ship was presented on the forum. https://wildfiregames.com/forum/topic/104332-naval-overhaul-alpha-27/ In my opinion, it is a great idea to provide the opportunity to capture an enemy ship. My development of this idea is very simple: Let's make this possible for the ship to be another ship with a garrison. For example: one ship that has no garrison (or fewer units) and another ship with a garrison (or two/three times more than the first) move very close to each other for a while, after which the ship becomes the possession of the player with a more powerful garrison. Much like taking over buildings. After capture, the first ship will receive part of the second ship's garrison. To do this, you don’t need to make animation, just add mechanics. Of course, it would be better to take into account the forces of the units located in the garrison, but only if it looked like hand-to-hand combat (without representing the battle itself, only capturing the line, as for buildings). And ships without a garrison could not be used for capture. Only for fights. Thus, the player can add units to the ship's garrison and go to capture another fleet. This will add dynamics and unpredictability to naval battles.

OK! Thank you guys. I'll investigate and let you know if I encounter any obstacles. Cheers.

In that python example they wrote a client with the endpoints IIRC You can run arbitrary JS with /evaluate and /step to make the simulation progress. Regarding saving the map itself I'm not sure you can do it one go might have to replay the map and save it after. You can load any map with that endpoint. If you're on Windows you might have some issues with python not going as fast as it can. Probably some issue with flushing.