A little ways down the road you’ll meet up with Shelinda and she’ll give you a little more information about what has happened so far. Make sure you take the trail off to the right (almost right beside Shelinda) to get a treasure chest that has three Lv.1 Key Spheres in it.
Further on down the road you will meet up with Biran and Yenke. They’ll talk more dirt to Kimahri and will confirm that the rumors about summoners disappearing around the area are true. Make sure you grab the chest behind them before you leave. It’s a good idea to get Yuna’s overdrive or any of your summons' overdrives as you will soon be fighting Belgemine, and winning this time is very important.
There is another chest on the way before you meet Belgemine on the right side of the path. A little further up the path you’ll meet Belgemine. Battle her Ixion, and if you win you’ll receive two Dragon Scales. You’ll also receive the Summoner’s Soul whether or not you were victorious and Belgemine will teach you how to use it.
Continue down the trail. One last chest can be found off to the left that contains a Magic Def Sphere. A little further on down the road and you’ll arrive at Moonflow.
When you arrive at the South Warf near th Shoopuf docking and loading area you can take a look at some of the items a few of the sellers have to offer, but a lot of the items are rather expensive. Go towards the left and you’ll hear a conversation between the Shoopuf driver and Captain Lucil about how they may not take the Chocobo on the Shoopuf. Grab the chest behind Lulu at the house before you leave and after that you can head back to the Shoopuf to start crossing the Moonflow. Just talk to the driver to get going.
During the Shoopuf ride the Al Bhed will kidnap Yuna once more. You and Wakka will have to fight a Machina underwater called Extractor. This battle isn’t too difficult. The Extractor only has 4000 HP, and if you have thunder element weapons for Tidus or Wakka they will do much more damage. Wakka should probably have a weapon called ‘Scout’ at this point that greatly improves his attack. Cast Haste on yourself to get a few more attacks on Extractor in less time, and watch out for depth charges as they may leave Tidus or Wakka temporarily blinded. And don’t worry, even though you can see Yuna above the Machina you don’t have to fear hurting her (it’s not like when you could hit Rinoa in FF8!).
After the battle Yuna will appear back onboard the Shoopuf. The Shoopuf will then continue its journey across the Moonflow.
When you arrive at the Moonflow take your team to the left and continue left past the Shoopuf. If you plan on playing blitzball I suggest hiring Miyu as your goaltender. She can be found on one of these screens on the way by and she is by far the best goaltender in the game.
There is also a chest beside Miyu that you should look into grabbing, even if you don’t plan on using her for blitzball. Continue going left until you come across Rikku. She’ll tell you about how and why she tried to take Yuna. The rest of the team will come up and meet her, and Rikku will offer her services to your team.
Once you’ve attained Rikku continue down the path where you found her which turns and heads north. As you can see, this is where they red arrow is pointing and is therefore your next destination. Don’t forget to grab the chest just off to the right. The first time you battle with Rikku on your team you’ll get a short little explanation on how to use her Steal command and Mix overdrive. At the end of the path is Guadosalam.