Courtesy of Walt Disney Pictures

Pirates of The Caribbean 4: On Strangers Tides is keeping production at full sail and sources tell HollywoodLife.com, “They are working day in and day out to wrap the project!”

Sounds like everyone is hArrrrd at work to get the fourth installment of the multi-million dollar Pirates of the Caribbean franchise finished and ready for it’s rumored May 20, 2011 release. On Stranger Tides is being shot in Disney digital 3D, making this the most time-consuming and spectacular production of the series to date.

With a rumored $200-million budget an insider tells HollywoodLife.com, “The Pirates set is crazy…they’ve been working 24 hours a day. The set is on the back lot at Universal Studios. There’s a HUGE green screen and the way they’ve built it, it looks like a cove. The director works for 12 hours and then the second unit director shoots for the next 12 hours.”

Production is doing it’s best to keep the set under wraps in one of the most tourist heavy theme parks in the country, which is tricky with heavy-hitting stars Johnny Depp, Penelope Cruz and Geoffrey Rush said to filming on the lot. Another insider tells us park employees are forbidden to divulge what’s going on, but are cryptically hinting to curious visitors about the set.

“The Universal Studios Park Tour takes park guests around the back lot and everyone keeps asking the tour guides what’s going on,” our source dishes. “The Pirates set is top secret though, so the tour guides are under strict instructions to not mention it at all. Some of the more daring guides will say, ‘I can’t tell you much, but I can tell you it’s rated Arrrrrrggghhh,’ like a pirate.”

Sounds to us like Disney is working overtime to ensure a 2011 summer blockbuster to follow up the massive success of this past summer’s Toy Story 3. Johnny Depp in 3D? Already sounds like a winner to us!

Aimee Curran, with reporting by Kirstin Benson