Opening tech path was (I think) mining->sailing->BW->masonry->wheel->AH->writing->Alpha. You can delay or skip entirely most of the worker techs because you a)wont need roads to connect your cities to trade routs because of sailing+coast and b)need only seafood and mines as worked tiles for quite a while.
The most crucial part of the strategy is of course...
Quite late especially with an Industrious leader on the map but there was a lot of pressure to grab the needed city sites so a lot of the GLH was actually completed with overflow from 2-pop whipping settlers. The trade routes allow us to tech fairly quickly while still expanding. And with few strong techers in the game I went Alpha first, and this is why you want to skip a bunch of the early techs on this map:
That trade coming after getting IW+ for alpha elsewhere, of course. With copper, all coastal cities each with at least 1 seafood to work, and no other AI having it I go for Metal Casting which nets me this very sweet trade:
Early math means my first GMerchant bulbs Currency. Our empire with the expansion phase nearly finished:
You can see there is a settler on the 1-tile ice island. It's a nearly worthless site normally but with the GLighthouse+offshore trade routes it will contribute about 10 commerce more than it costs me as soon as it's settled. The crappy barb city remaining to the north is captured shortly after this screenshot for the same reason, and also unlocks the Heroic Epic for me. So this map allowed me 10 cities, all coastal, with only 3 of them not really being able to contribute hammers.
Why going for MC (especially being able to trade it for math+) was a strong move:
Copper, math chops, brokering MC for numerous good techs, and so many water tiles being worked that the Colossus immediately gives me about 20 extra commerce per turn. The tech situation after my first GScientist bulbs Philo:
So I was first to Currency, CoL, Philo, AND Metal Casting, with zero cottages and only one commerce tile in the entire empire. The power of GLH abuse, which on this map is almost as good as it would be on an archipeligo.
I thought this was kind of funny:
Barb Galley spawn where it cannot move. This is also quite helpful, because no more barb galleys could spawn up there.
The game at this point would ordinarily be your standard bulb/tech your way to a Military Tradition lib and then roll up the map, but in this case we have no horses, and only one AI with multiple sources who will not trade them to us. The easiest solution is a detour through machinery->engineering to get our hands on them the good old fashioned way. The target is Hannibal:
He was going to be the target anyway, but actually declared on me while I was preparing, which was fine. I bribed Saladin on him which kept a lot of his units tied up if only for a few turns. Why Hannibal? He has horses, he has a bunch of techs we want, and his land is nice (particularly the gems, because all my cities have forges). His cities are also placed such that I can hold on to them without much culture pressure at all. I take him down to 3 cities and he capitulates.
While this is happening I bulb education. Now ideally I would self tech or trade for nationalism and lib MT. But Hannibal and a couple others already have nationalism, and there is one AI that can already research Lib. This makes nationalism a very poor choice, and makes it far too risky to try to lib Replaceable Parts. So instead I Lib Printing Press, which nobody else has, and put a bulb into Chemistry instead. Which allows me to make this trade with my vassal:
So now I can have Hannibal research MT while I do Replaceable Parts to trade for it. I can make Hannibal give me his horses, and I should have time to vassal one more AI with cuirs and then finish the map with either cavalry or cannons.
That Lib date was probably only possible because the entire world was at war for quite a while.