Jak and Daxter: The Precursor Legacy/Sentinel Beach

Unblock the Eco Harvester
After you return from Geyser Rock Samos tells you that his green Eco harvesters on Sentinel Beach have been clogged up and wants you to unblock them. There are five harvesters. Just hit the rocks underneath each one. Once you unblock the last harvester a power cell is released.

Get the Power Cell from the Pelican
On the beach where the Cannon Tower is shooting at the metal boxes is a power cell. When you get near enough to it a pelican swoops in and snatches the power cell into its mouth. The pelican lands in its nest in the middle of the lagoon. Swim to the pelican and give it a smack. The Pelican spits out the power cell and the power cell flies towards a windmill on top a small cliff side. Quickly swim towards a two small spinning platforms by the windmill to get up the cliff. Grab the the power cell before the pelican or else the pelican will scoop back up the power cell and you will have to start the process over again.

Chase the Seagulls
At the end of the beach you will see three pyramid like structures lined up near the water. On one of them there is a flock of seagulls resting. Daxter will spot them and want you to chase them for fun. After doing so let them land on the next pyramid then chase them off again. Do it on last time when they land on the last pyramid. The seagulls will fly off causing a rock slide near the Eco harvesters. The rock slide will release a power cell.

Explore the Beach
Near where the cannon tower is shooting the metal boxes, there is another power cell on the beach. This one is located at the back of the beach, in a small cove. In that small cove is a power cell. The power cell is easily visible and is hard to miss. Just be careful, there is a serpent lurker hidden in the sand that will pop out when you get close to it.

Climb the Sentinel
The pyramid like structures where you chased the seagulls are the Sentinels. Climb to the top of the center Sentinel for a power cell.