It seems that in the inner sea maps, the contacts are significantly delayed compared to Pangea
On the contrary, it's easy to get contact with everyone on an inner sea map, because you know exactly where everyone is! Just stay close to the water (shortest path) and keep your warrior on hills/forests/jungle as much as possible.
I'll be sending off 2 warriors - One will charge around the sea, the other will explore close by, and then head the opposite direction to the first warrior. Once they meet, just set em to auto-explore, then disband them when they get hemmed in (assuming you don't have open borders with everyone). I'll probably also have another warrior to suss out the nearest neighbors and then fortify on a wooded hill close to my city as an anti-barb measure.
Potenital slingshot:
Well, I wrote the following as a description of my Civil Service slingshot, but it got a bit out of hand. Hopefully its useful.
I saw a few people discussing this. Not sure if the following is what you meant, but it works good for me. Youre going to be cottaging most of your land early on, so I honestly dont see the point in going for BW. This strat is a bit risky, you will hurt if you miss out on building the Oracle. You also need to watch out for barbarians, and chop archers if you have to.
I've been playing a one city start, cottage spamming and researching pottery -> writing -> alphabet with a single city. Try to have 2 workers and the above 3 warriors, and some shields into library by the time you finish alphabet. You want all the contacts if possible, and I've been getting open borders with everyone but my closest neighbours. I didn't bother having any defence in my capital until after I saw the first human barbarian.
Start trading for techs, focussing particularly on getting Meditation and Bronze Working ASAP. Finish off your Library, and your capital should have a healthy 25-30 research per turn. I've found that you have to research Priesthood yourself, as it takes ages for the AI to trade it to you.
Research Code of Laws as fast as you possibly can. Forget growth or shields, just get as many cottaged squares worked as you can. At the same time, chop another worker (and an archer if you really need it) and then the Oracle in your city, timing it to finish the turn you finish C.O.L. (Later on, use the Prophet from the Oracle to build the Kong Miao.) Dont make Confucianism your state religion unless you think its worth it (probably not at this stage) Take Civil Service as your free tech. Switch to Beurocracy.
Now research metal casting -> machinery, and you should be easily able to trade for everything else you need (which is mainly IW and Construction). Chop ~3 settlers with archers, and set these cities up in high-shield areas (be sure to grab some iron!). Theres no need to spread these cities out, just find some spots on rivers with nearby hills, and preferably lots of forests. Now be sure to improve some high-shield squares around your capital with Beurocracy and a forge you can get to 100 shields/turn. Chop barracks and axemen/catapults until you get Samurai. Once you have 5 Samurai, you are set to start expanding. Build Heroic epic in your capital.
Cottage spam in most cities you capture, and chop markets/banks, or upkeep is going to kill you. Note that you can probably afford to turn research down for a short period of time you should still have plenty of techs to trade getting Civil Service early is a huge bonus, as it can usually be traded for 2-3 other techs. Find one city with good food output and make it a GL farm. Early on, choose 5 cities for courthouses and get those build quickly so that you can build a FP.
I quit my test game after taking Qin and half of Caesar (praetorians make it difficult to hold cities!). You are well set up to beeline for Military Tradition/Gunpowder and Cavalry.