It's impossible to go to GM island using old ways.
The blue walls are gone, replaced by totally invisible ones (you can only see a black dots line on the sea that marks the wall position), which are impossible to get through. I tried blinking, offline MC, offline Crashin' Thrashin' Racer, DMF tigers, Farclip Bug, going very high or deep in the sea, offline Doctor Weavil MC, went to death floor offline and the wall is still there.
The only way I found is Control FP, who can get you to GM island if you have an hour to lose. I also tried letting a controlled FP dismount me behind invisible walls but got insta DCed. I really don't think there's a way of getting to GM island online atm. But i'd be very pleased to be proven wrong
