When this happens, the first and instinctive action is to remove the battery and place the phone under the sun to dry. Hmmmm!!!, this of course is what a guy would do. But I think a lady would cry her eyes out first. (My sentiment).
But drying the phone in sunlight means causing more harm to the phone.
Here is a more economical way of trying to rescue and save the phone;
1. Quickly take the phone out of water. ( Avoid the temptation of pressing the buttons to see if it still works)
2. Remove the battery and SD cards (memory card), SIM cards and every other attachments. [If the phone has a non-replaceable battery like the iPhone, then this is not an option. Just turn it off].
3 Dry the phone with a towel.
4. Dip the phone into a bowel of rice. (Whaaaaat?). Oh Yes, you read that correctly.
Rice is a good desiccant material and has good hygroscopic properties (That is, it tends to attract moisture to itself and absorb them). Silica gel is also another example,
5. After a while bring your phone out and replace battery. (Close your eyes and pray).
6. Turn it on. (wooow!!!!, it's working)
Share these and let's know how it works. Suggest other tips you may have.