report that Hearn said he is coming up with "quirky ideas" about where to stage the heavyweight king's big return.
AJ was set to defend his WBA, WBO and IBF belts against Pulev at Tottenham stadium last month but the coronavirus pandemic KO'd that.
Now, Hearn, who is staging Fight Camp in the garden of his Essex mansion, is thinking outside the box for Joshua's fight, scheduled for November.
He said: "Other ideas we have are 1,000 people somewhere strange and quirky. I’ve got a few things up my sleeve. We’re talking about castles, plush hotels, maybe even on a boat.
"Croatia have offered a coliseum — and that’s beautiful —and we’re still open to options and flexible.
"These are all things thinking outside of the box — it just depends what’s allowed."
London's O2 remains the most likely venue, but Hearn added that much depends on whether social distancing restrictions are lifted.
He added: "By November, can we go to 16,000 people at the O2? Right now, we’re handcuffed by the regulations."
As far fetched as it sounds, fighting on a boat has nearly happened before.
Joshua's heavyweight rival Tyson Fury - who has agreed to a two-fight deal with AJ - claimed he was offered around £82million to fight Wladimir Klitschko on board a luxury superyacht in 2016.
say a Middle Eastern sheikh had offered to stump up the cash for the Gypsy King to take to water - but it never happened.
Joshua recently kept fans updated on his progress ahead of the bout against Pulev.
The 30-year-old was branded the "hardest hitter on the planet" after he smacked a punching bag while sitting down.
Watch Anthony Joshua's explosive power on punch bag while SITTING DOWN as fans fear how hard he can hit while standing