I lost my boat in the swamp after using statue of adah. Is it bug?
I had the same problem, and found a fix for this. I edited my save to put the boat back to the accessible position it starts in. I couldn't just use the rpgmaker save editor tool posted in a thread here here, I had to go to a website (don't think I'm supposed to be linking such things, so you'll have to search it) called save-editor (.com) which let me decode the entire save file to a text file, then I found the boat with ctrl+f and edited its location. The way I did this is:
1) It's actually the "ship" entry right below the "boat" entry, but you want to search "boat" since there's only one hit for that and a bunch of "relationship" stuff that will come up if you search "ship".
2) Within the "_type":"ship", entry (everything between the "@":"Game_Vehicle"} lines), you need to change x, y and realX, realY both to 11, 2 and you need to change mapId to 90.
I did this, added ".bak" to the name of the save file I originally uploaded, uploaded the edited text file to the site, re-encoded it as a save with the same name it originally had, loaded the save and the boat was there. Obnoxious, but it worked and saved me throwing away all the progress I made after bugging the boat.