Some of them are dangerous in that way, sure. Some of them are just very unpredictable and it's easy to get lost, and some of them might wind you up in the Calm Belt which is never a good place to be. [With that name, you wouldn't think it'd be bad, but hey.]
For the record, my ship was mostly made out of metal. It was a submarine. [So don't go thinking your metal boat technology is so unique, Ren!!!]
As far as the number of countries, I've no idea. No one's ever mapped the entirety of the Grand Line. I believe the world government contains about 170 allied countries, but that includes ones from the others seas, not just the Grand Line.
no subject
[With that name, you wouldn't think it'd be bad, but hey.]
For the record, my ship was mostly made out of metal. It was a submarine.
[So don't go thinking your metal boat technology is so unique, Ren!!!]
As far as the number of countries, I've no idea. No one's ever mapped the entirety of the Grand Line. I believe the world government contains about 170 allied countries, but that includes ones from the others seas, not just the Grand Line.