Like the ones mankind has made. every single design.

Ponykind possess no naval power, at least as of yet in the series. But in terms of how both ponies and Griffons will have naval power, they would go significant boom in the Industry, preferably an Industrial Revolution, then building ironclad battleships, like the Dreadnought.

@AaronMk  
That’s not entirely historically accurate, although it’s what has frequently been taught. While some battleships were destroyed by planes, the process was slow and uncertain, it was rare, and even more rare that they were destroyed entirely by planes (except when in harbor). Under way, battleships were not only rarely victims of aircraft, they were very effective anti-aircraft platforms responsible for defending other ships from planes.
 
When aircraft could hit targets many tens, or even hundreds of miles away, battleships primarily became useless as first-strike weapons of power projection. Carriers could always out-range them. And since a big part of a battleship’s defense was that their guns out-ranged the guns of everything but other battleships (hence, they only really had to be self-protected against other battleships), aircraft took away a lot of their protection in addition to supplanting them as the main arm of power projection.
 
But they were far from useless. The three best anti-aircraft platforms of WWII were the Atlanta class light cruisers someone mentioned below (more 5” long-range AA than anything else), the Alaska class heavy cruisers (more 40mm light AA than anything else), and the Iowa class fast battleships (more 5” than the Alaskas and more 40 mm than the Atlantas.) The Iowas had the added advantage of being able to repel surprise attacks by other battleships. Although the argument could be made that those attacks almost never happened, one of the reasons was that the fast carrier groups always had their battleship escorts. An enemy battleship taking on a fast carrier group would have to fight both planes and battleships at the same time, something that posed significant difficulties. Take away their battleship escorts and the fast carriers would have been juicy targets for a sneak attack by battleships. By preventing attacks by battleships on the carriers by virtue of their mere presence, the battleship escorts were more effective than if they had actually fought off other battleships to protect the carriers. One complication is that other than the Iowa class, America’s battleships were built to a doctrine of engagement based around moderate speeds and large fleet sizes, and couldn’t keep up with the top speeds of the fast fleet carriers. Slowing down the fleet carriers just to be able to use the South Dakota and North Carolina classes as AA escorts made no sense; they would have been more vulnerable due to the restriction on their speed, almost in proportion to the greater protection afforded by more AA picket ships. Therefore the rest of the battleships were used, to great effect, primarily as batteries for shore bombardment ahead of amphibious landings.
 
So battleships weren’t useless, they were just relegated to support roles where they were still incredibly useful. They were, however, far too expensive for the support role, which is why no more of them (nor any more giant armored cruisers like the Alaska class) were ever built.

Considering that Rainbow Dash has mentioned “Big Guns”, “Tanks”, and “Fast as a bullet”, I personally think that their battleships would look like the ones mankind never built, like the American Montana Class, Japanese Super Yamato, or German H-Class. Might I also mention in the episode “Spike at your service”  
Spike says to Applejack that “She racketed those rocks like they were rockets!” After she saves him the first time. Which brings me to my next question, what about high-fragmention rockets?

If their magitech level is on WWI, it would make a brilliant warfic if the story is about a crew of ponies on a new, revolutionary dreadnaught class vessel.

Can’t Gryphons also control the weather like the Pegasus ponies do?

The coastal cities and towns also don’t look medieval, spartan, or arcane as the main settings of the show. In fact, they look kind of modern with skyscrapers like typical modern cities in real life.  
I do think they have some sophistication in technology in areas mostly populated by Earth Ponies and Pegasi. But, in cities like Canterlot, with large, rather conservative, Unicorn population find little need of those clunky machine when they have magic.

Wow was my memory of that map bad. With that in mind, my new strategy would be to place a naval blockade around Griffon country. Individuals may be able to fly past it, but an invasion of Equestria would require ship loads of supplies. Fighting the Griffons in the air with pegasi is tactically unsound due to the average Griffon being larger then the average pegasus and in possesion of clawed hands. Thus, raiding teams of unicorns and earth ponies would strike under the cover of darkness for surgical strikes against the military and leadership.
 
If the Griffons are defeated, an influx of supplies, combined with a propaganda storm and providing war times attacks were kept aimed at military and government officials could turn the civilian masses against the military and government, creating a de-militarized ally and trading partner within 25 to 30 years.

As WW2 taught us in this world navies sort of fall apart when air-combat comes in. When aircraft came into heavy use battleships weren’t much useful.
 
It’s pretty possible that navies would drop to a secondary level importance, if not all the way to something like specialized auxiliary in a engagement that’s highly likely to be air-borne.

@AaronMk
 
My question is, why are they avoiding to make the Mane 6 from traveling to the coastal areas in the show?  
Rainbow Dash mentioned in “It’s About Time” that she has flown of Fillydelphia ot Los Pegasus. But, we have yet to see the sea and coastlines themselves in the show. Ships that float on water haven’t really been seen in the show either.

@AaronMk
 
The scenario you foresaw sounds very plausible indeed, Still I think they would give equal or similar importance to both navy and air force.

American Civil War era ironclads.

@Vlakc.
 
Yeah, I foresee more an importance in aerial combat than naval. If such a war were a thing, and the griffons are across the sea we may see some early usage of naval craft. But probably as a momentary place-holder until the air-ship fleet can be assembled or built upon.
 
My prediction: first year or two will be with naval craft to get Pegasi close to Griffon lands or cut them off mid-sea as the fly over. In this time, air battleships will probably be commissioned for development to ferry significant non-pegasi forces across.
 
In the event of this war I would play it defensive during the pre-airship period as projects to construct battle-worthy airships are carried out so I can reliably fly stuff over to them via Hindenburg-like fortresses. Preferably with magical fail-safes to keep them from bursting hilariously into flames.

@Kappe:
 
You make a good point, I agree with you mostly, because having ww1 era warships seems a little unbalanced with the rest of the military (as far as we have seem they still use spears and the like), so I’m gonna go with what I posted first (greek ships) at the very least, and what you posted earlier (not ironclad steam power) at the very most.

Most of you are thinking way too modern/futuristic. Nothing in the show suggests that technology in Equestria is anywhere near present-day, let alone the future.
 
Flim and Flam’s machine appeared to be steam-driven, and the airship in Sweet and Elite looked to be propelled by fin-like paddles. The floats, on the other hand, definitely ran on gasoline (or diesel) engines, and if Dash’s pet is any indication, apparently some military power has tanks.
 
Since the levels of technology in the show seem to fluctuate between applications, naval vessels could resemble anything from the picture I posted earlier at the very least, to the time of WW1 at the very most.

@WatermelonRat:
 
That could also work.

Korean Turtleboats.

@Trickquestion:
 
>>68332
 
No equestria is not landlocked, and by what the map suggest, The griffin lands are either an island or are at the other side of a gulf/bay, it appears also that both nations do not share borders, with this, naval warfare is mandatory.
 
Your plan although good, seems to me a little far fetched because, the griffons can also fly and they would have better knowledge of the terrain, and it will just take a little bad luck for the special teams to be spotted and then have an entire battalion at their backs.

@SeraphimDawn
 
Does anyone have that offical map they released ago? If they do, is Equestria landlocked? And dosen’t it also say the Griffon kingdom is in the mountains, where battleships would be ineffective?
 
If Equestria cannot convince them to back down by dropping the sun on them, I would advise small teams of unicorns and pegasi to enter the enemy homeland discreetly, and use magic and weather control to cut supplies and wreak general havoc amongst the civilian population, lowering support for the war amongst the civilians and requiring a portion of the enemy army to stay home. Earth pony guerrillas would hold the line in Equestria.
 
Mobility and magic would have to be the cornerstone of Equestrian strategy, seeing as they completely lack the neccesary industry for conventional warfare.

I on the other hand like to consider that, since equestrian military fashion seems greek-ish, and their military technology seems underdeveloped in comparison to the other branches (they still use spears etc etc)
 
Therefore I like to think their ships will be inspired by ancient greek ships…
 
 
 

 
And at the front it could have a unicorn head a la viking style for aesthetic and ramming purposes
 
Here is a link if you want more information
 
Hope this helps you.

@Seraphim
 
Manehatten is actually on an island according to the canonical map of Equestria. As are many other major settelments mentioned in the show.
 
Looking at the map all the inland settelments are minor, save for Canterlot. But since that’s the seat of government it’s sort of the exception to the rule.

A little off topic here.
 
Does Equestria even have a Navy or seafarers? Is there any reason why they put the main settings so far inland? It’s as if the writers are so afraid of the coastline that they don’t want an episode that takes place at a setting near the sea. We have yet to see what the sea on their planet looks like in the show.

 
For added nuclear strike capability.

Either way, the ponies are screwed.

“@Dawn Blast”