ROLLER COASTER fans know the moment of truth: when the car is at the top of the hill, and you're staring straight down at the drop.

Now imagine you can't see the drop.

That's what happens at Skull Mountain, a new roller coaster that whooshes and wlzzes riders around in cornplete darkness.

It's one of three new spectacles at Six Flags Great Adventure Theme Park in Jackson, N.J., where this summer they've pulled out all stops. Apart from Skull Mountain, there's the new action-packed water show, based on "Lethal Weapon" movies, and Masters of the sky, a show featuring real life birds of prey.

Which means thrill seekers, bird watchers and everyone in between will find something to entertain them.

Here are 20 fascinating facts that all three new events in store for fun seekers this summer.

1. The waiting line at Skull Mountain can stretch to 1,000 feet and numbers up to 1,000 people. But don't worry: The three trains, holding 28 people each, shuttle riders at at rate of 2,200 passengers per hour.

2. The dock explosion in the Lethal Weapon show is ignited by a propane line, and the billowing flames reach a scorching 2,000 degrees F.

3. The heat from the blasts reached such extreme temperatures in rehearsals that the paint originally used on the set blistered and finally burned off.

4. In the "Lethal Weapon Show," Martin Riggs is played by two Mel Gibson look-alikes, Carl Cannady and Jeff Knippen. Terrence Kelly and Dez play the Danny Glover character. Roger Murtaugh and two dead ringers for Joe Pesci play the blond perennially chattering Leo ("Okay, Okay") Getz - Emory Bottorff and Art Morrison.

5. Once Riggs' trailer home blows up, look for a toliet and a box of Milk Bone dog biscuits in the rubble. "Lethal Weapon" fans will remember the tense moment when a ready-to-detonate bomb trapped Murtaugh on the toliet in "Lethal Weapon 2" And dog biscuites are the favorite snack of the ever destructive Riggs.

6. In the Masters of the Sky exhibit, a griffon vulture- which has a wingspan of 7 feet - soars mere inches over the audience's head. It is the highest-flying bird on record, known to reach altitudes of 37,000 feet.

7. None of the birds in the show were captured in the wild. All were born and reared in breeding programs and zoos around the country.

8. The rocks in the ominous- looking Skull Mountain are not rocks at all. They're actually made from carved foam.

9. The Skull Mountain ride - staged as a mine-train car gone haywire - lasts less than minutes, but reaches a top speed of 33 mph.

10. Screaming riders aren't the only ones making a racket inside Skull Mountain. Listen for howling monkeys, roaring tigers, jungle drums and other wild noises.

11. The tiger tracks that lead visitors up the jungle pathway are legit - cast from the felines in the neighboring Wild Safari Animal Park.

12. Foghorn Leghorn will take heart when he learned from Masters of the Sky that there's no such thing as a chicken hawk - that pestky little bird that's always foiling our favorite rooster of cartoon fame. Truth is, hawks steer clear of chicken and sticks to rodents.

13. That's no comfort to Mickey Mouse as hawks eat approximately 1,000 mice a year (and the buzz is they taste just like chicken).

14. In the "Lethal Weapon Show," a 40-foot-high voltage tower blows up and collapses into a lake. A second explosion sends a 30-foot ball of flame into the sky.

15. In a daredevil stunt, a motorboat crashes though a yacht - flying 10 feet in the air. It's the highest boat jump ever to be staged on a regular basis.

16. All the pyrotechnics in the "Lethal Weapon Show" are computer controlled. There are more than 40 hits - including blasts, gunfights and fireworks.

17. The jumping fountain, on the way out of Skull Mountain, features a spout of water that leaps over 10 feet, dancing from one of three wells to the next.

18. The entire cast of the "Lethal Weapon Show" consists of stunt professionals, but they don't all come for a showbiz background. Most are ace water skiers, expert at handling the tricky boat maneuvers.

19. Lolita, the yellow-naped Amazon parrot in the Masters in the Sky, learned how to bark, meow, and say her name from another parrot. She's trained to speak after certain words. Say her "cat" and she'll meow.

20. For the birds in the show, it's a case of trick and treat. If they do the trick properly, they're rewarded with a tasty bird treat, like a morsel of meat or some seeds. But no trick, no treat.