Dorne is a desert with a prominent coast and rivers. You'd think they'd have "naval tradition" for the sake of getting around if nothing else! Shit even places where the ground isn't mostly fucking sand heavily used water transport!
Hey, you know who also was a prominent, rich desert country with prominent coastline and no naval tradition? Ancient Egypt. Of course, after Alexander you got Alexandria and the Ptolmaic navy, but both the city and the ruling house were heavily Greek. During the native dynasties, during the Old, Middle and New Kingdom, Egypt's armies could, at times, hold sway from Nubia to the Levant... but they barely had any presence in the Mediterranean at all.
In a way, especially because being a desert forces you to be a land power. You can't control vast swaths of worthless land with a navy, and you won't produce enough surplus for naval trade anyway. Even coastal raids are made a non-factor by that. If your coast is just empty desert, what's there to raid?
And Dorne's coast is in fact mostly useless. Most of the coast is the southern coast, and that is all desert with few locations to even so much at take in fresh water, never mind anchoring places, and difficult currents besides. This makes it really difficult to transfer from the continent's western to eastern coast, in fact, and crossing Dorne's southern coast even was a challenge to Victarion's Iron Fleet. There is ocean there, yes, but no harbours or ships or even just fishing. Because the coast is all empty desert. Not unlike, in fact, Egypt's coast west of the Nile delta.
And the western coast is all mountains and easily blockaded by the Reach, of course. Of course, yes, that leaves the eastern coast, where the area is not quite as deserty, where you have access to the busiest ocean of the world (the Narrow Sea), and where the Stepstones are right in front of your face. But I think that may be part of it. Difficult to get much shipping done when you are in pirate waters as soon as you leave your home harbour.
Like, "naval tradition" doesn't just mean navy - it means
ships, period. As in, of course, Planky Town and the Shadow Town have harbours where trade ships come by, but it's nothing compared to the Free Cities or King's Landing. Even in just trade or fishing ships Dorne doesn't have much of a tradition, so what would they need warships for?
So yeah, I think Dorne's lack of a naval tradition is adequatly explained by the geographic details we're given.
Like sure the North doesn't have a western fleet but per Canon Asha's pinecone speech at least theres the excuse of there basically being nothing there!
Asha advocated settling there, and that there are enough riches to house the whole Iron Islands population all over again. Meanwhile, "nothing there" is indeed
exactly the argument for 3/4 of Dorne's coast. Only the areas around the Arm of Dorne, with locations like Sunspear and the Tor, have anything at all at the coast.
Oh and also:
[X] Accept them as is