Speaking solely from a single-player deity perspective...
I'm glad this thread was necro-ed because I think there's a bit of confusion regarding some of the terminology and consequent tactics. The VAST majority of the Civ-tubers exacerbate the issue as they much prefer land-based combat over naval combat.
"Winning a game wherein the majority of combat is naval" and "playing a game where you never build a single land combat unit" are two different things. Yes, for naval-based domination games it's usually necessary to have some degree of a land army. And yes, if the AI settles their cities a tile or two in from the coast, you will need a paper unit to take the city. But despite both of these truths, naval domination is not only viable but (in my opinion) FAR easier than land-based domination. Leading into the second point of clarification...
..."Using combat to basically bulldoze the map and burn down or capture every AI-settled city" and "winning a domination victory" are two VERY different things. If you like steamrolling through AI territory and ROFLstomping every unit that they throw in your way, then have at it; everyone is entitled to play and win the game in whatever way pleases them. But, this is in no way necessary to win a domination victory. A domination victory is triggered by taking possession of every AI capital. Period. It's not necessary to do anything to any of their other cities, and it's possible (however unlikely) to win a domination victory without ever destroying a single unit (unless its in their capital.)
Taking these two points into account, I find naval domination to be much more fun and much easier than land domination. When you decide to share vision of capitals with the AI, you can see where it is and the 6 tiles surrounding their capital (though it gets a little more complicated if they lost their capital and you only get to see their current and unoriginal capital. Anyways...) make a note of which capitals are coastal, you can disregard these civs for now and even establish friendship and alliances with them, boosting your trade yields. The civs that don't have coastal capitals are going to need some bulldozing, but often when you scout out their territory, you can find a path to their capital that involves only having to work through one city if any at all. Then, once the non-coastal capitals are out of the way, build or buy at least 3 naval ranged units and one naval melee unit PER AI CAPITAL REMAINING, and move them into position. Naval rangedunits must not suffer the same penalties attacking cities as land units as I find they melt through city defenses much easier than land units do, even without the support unit bonuses. DoW every AI with a capital remaining and take it in 1 or 2 turns. Domination victory triggered.
Now on coastal maps (particularly island plates and archipelago), this can lead to a very different domination experience as the lack of tiles that are far inland makes for most or all of the AI to settle their capital on the coast. If every capital is on the coast, then you can play peacefully and trade and sim-city your way to incredible infrastructure for the entire game... except the last two turns where you DoW everyone (which may entail waiting for an alliance to expire) and take every capital on the same turn one turn later. I find the advent of frigates to be the sweet spot as they are the last naval ranged unit you can make without having the units consume resources. Naval units also arrive at their destination much quicker as they have more movement and there's no water terrain that slows movement. This is a method of enjoying the fruits of peaceful interaction with the AI for basically the entire game and still be able to trigger a domination victory. If there are one or two AI that settled a bit inland, it'll take a few ,more turns as you move your land army into position and DoW them a few turns earlier to work your way to the capital. Once you get there, don't take the capital (and suffer the consequences of doing so) until you've dowed everyone else and have your navy work ever capital down to 1HP. Then take them all in the same turn.
This is obviously a strategy that doesn't work in multiplayer, but if
@Victoria says naval dom is viable in MP games, I'll take her words to the bank.