On "Little Resistance", after calling in the air strike, proceed to the right of the beach, there should be a puddle there. Go in.
Get out move to the left and you will see another puddle. Go in that one. Then on the very left side of the beach, close to the shore, there will be a crater. go in and after several seconds, you will hear some Japanese voices and statues will come out holding ray guns. Or you can use the "give all" cheat. Bonus: At the end, when you have to call in an air strike on the tanks, shoot them with the ray gun instead. It will destroy them!