That door was easy you got past; Unfortunatly your first and your last.
Past the fifty note door should be the puzzle to Treasure Trove Cove. Fill in the missing pieces. Go up the ramp in that room. The next room should have a river. Jump into it and go over the waterfall. Jump out of the pool of water and there should be a door to your left. Go into it and jump into the big treasure cheat.
Avast, ye mateys! There's no treasure here. The only booty is mine that's kicking your rear!

Moves
FlyingFind Bottle's molehill on top of the ship's sail post.Press A to take off and A to flap your wings while flying.
Shock Spring PadFind Bottle's molehill on a ledge near the entrance.Hold A
Jiggies
Shell it out - Rat-a-tap-rap Nipper's eyes three times. Then go inside his shell.
Kindness Plop - lay two eggs into leaky the bucket. Go into the sand castle and spell out Banjo-Kazooie.
Leaping for joy - Using the spring pads, climb to a ledge on the mountain.
Pond-ering - dive into the pond at the top of the hill.
Backside - Near the ladders, follow the ridge around to a cove on the backside of the mountian.
A Sad Seaman - Find the two gold pieces within Blubber's ship. One you have to break a pannel on top the mast, the other you swim in through the window.
Flying - from the pad up top the ship's sail pole, fly to the cove on the left.
Light it Up - from the pad up top the ship's sail pole, fly to the cove on the right. Make your way up to the door of the light house. Beak Barge it, and climb to the top.
Treasure Hunt - A top the green tower, stomp the red X. Follow the clues. Beak barge the chest that appears.
Jinjos - One is under the dock where you start. One in on top of the ship's mast. One is on a platform extending from the mountain, near the highest pool. One is near the shock spring pads. The other is on a tree near the light house.

Notes
4 - entrance dock
12 - platforms (16)
3 - rock pool with crab (19)
12 - ladders (31)
11 - rigging on ship (42)
8 - on 2 palm trees (50)
8 - cargo hold (58)
3 - flight platform (61)
4 - jetty to tower (65)
6 - hexagon platform (71)
5 - treasure chest (76)
1 - entrance to lighthouse (77)
3 - spiral path to lighthouse (80)
5 - top of lighthouse (85)
5 - sandcastle in pool (90)
4 - inside sandcastle (94)
6 - inside Nipper (100)

Extra lives
One's on a box by Shark Food Island
One's on a ledge on the mountain
One's between the platforms leading to the green tower

Extra Honey comb pieces
#1: Jump of the cliff near the lowest pool
#2: On a crate off coast from where the treasure hunt ends.

Witch Switch
Behind the light house. Exit Treasure Trove Cove, and flip up on the extended canon to get on top of the ship.

Fun Things
Banjo Falling - Fly as high as you can go, then use the beakbuster into the water. Banjo will scream and wave his arms, but won't gain damage.
Kill Snacker - Stand on the crate near Sharkfood Island. Jump into the water. When Snacker appears, shoot ends at him with the C down shot. Repeat until he dies, leaving three honey combs.