Crossing The River
You will need to build a bridge of boxes along the white arrow. Start with boxes 1 and 2, SpongeBob can move these on his own. Then step on the green button and have Patrick push box 3 into the water.
Next, have Patrick push box 4 into the water at position "A" and place him next to it at position "B". Use Spongebob to push box 5 to postion "A", and Patrick can now complete the next part of the bridge. For box 6, use SpongeBob to push it one step aside, then place SpongeBob at position C. Use Patrick to push the box back into position - SpongeBob can now complete the bridge.
To pickup the Bonus Bubbles, leap-frog SpongeBob and Patrick through the blue "X"s to help push the box along the blue path.