Gears of War 3 Game Guide

Act Two: Chapter 1 – Shipwreck

As the level starts, find the brown container nearby and open it for a note.
Pick up the guns as you move, including two lancers, two pairs of frags, and
a handy longshot; there are many more guns in the muck, but you don't need
them all. When you reach the main area you will face two groups of grubs, and
then a final wave who appears from behind a collapsable wall. Save the longshot
for the final two waves, and you can flank them to the right, but you can also
be an easy target if not careful. After the fight, don't worry too much about
ammo as you just need to kill one more group ahead. Move up the path and get
ready for Locust to emerge, one on the container at first and then more behind
the sandbags. Mop them up and go behind the rock to pick up a note. Move 
forward to swap bodies, even on co-op.

Begin pouring lead into the Diggers and their friends. The Digger Launchers
can go underground and ignore cover, but they don't seem to go under rock 
barriers. So dodge the diggers and run up to the right where Grubs will emerge,
but you need to take out the snipers on the bridges above, or stay out of their
sights until the Drones are dead. When you have this narrow passage clear, 
turn the corner and finish off the Diggers and the Locust behind the sandbags.
Careful when you go to collect ammo as your team may engage the Grubs up the 
trail, including a sniper on a bridge, and that will cause more to emerge from
the middle of area where the Diggers were, so take them out quickly and feel
free to use the digger guns; but again, you'll have to grab them fast and get
ready. Feel free to bring a digger gun and boltok.

Collect the frags and ammo before moving up the trail to the siege crews. Mop
them up and drop down. Before you jump on the siege beast, move up and then
look right and up to see a box on a cliff side. Destroy it and a note will drop
that you can pick up in a minute. Get on the siege beast and destroy the other
two catapults as Grubs will be incoming; on co-op have someone ready to saw 
them apart as they come up. Then a Brumak will appear that takes a few hits of
artillery to kill. Grab any ammo before he dies if you need it.

*NOTE: If you want to conserve lancer ammo, feel free to use the boltok as you
have a lot of allies in the fight upcoming.*

After the scene, move up and and have a frag ready for the Locust that pop up
in the alcove on the right. You can hit the box on the cliff now, and if you
hit it before you can pick up the note in the alcove. Grab what you can and
continue down the trail to engage two snipers in  the cliff wall. Three more 
are around the corner. Move up to be behind two Drones who are more concerned
with the COG on the beach, so pick them off and move up. When the next enemies
emerge, they will fire at you, so take them out quickly.

After the scene get ready for a long stream of Grubs, so sit back, mow them 
down, and don't let them get too close. Be sure to grab the COG tag behind the
container on the right. After you kill the ones that appear farther back, a 
Brumak will appear. You really need to stay safe here and behind the cover of 
a container. You can temporarily disable his arms, but just focus fire on his
head. There is ammo at the back, so just don't stop the stream of bullets.