Water Temple - Stage 1
Take two heroes and have each of them grab a gripshot. Use that to latch onto the grate across the water on the left and right sides. Next have these two characters stand in front of the orb on their side and hit it with the gripshot. This will raise a platform to which you must send one person to stand on and pull at the wheel to raise the water level. Finally, Go ahead and have the item-less character swim over to secure the water rod and head for the gateway, to complete the level.
Water Temple - Stage 2
Send all three heroes to step on the big switch to raise the water level and summon some monsters. Defeat them then pull on the water wheel to the right to make the water recede. Next swim under the grates on the left and make your way up with the water rod to the next wheel. Stack two gripshot characters then boost them with the water rod so they can pull the wheel. This will cause the water to rise again allowing you to reach the gateway and proceed to the next stage.
Water Temple - Stage 3
Fire the gripshot at the middle section of the grate to get both of the gripshot characters to the other side. Have them step on the switches to open the gate. Next, use the water rod to reach the higher platform to the left then pull on the wheel to raise the water level. To the left is another grate that gripshot characters can get through so use the water rod to get them over. Stack two guys to grab the key and open the gate with the switch on the floor. With the key in hand head over to the door.
Water Temple - Stage 4
The boss for this level is Arrghus and it has three forms. To start things off, have a gripshot hero yank at its eyes and slash the with the sword until they're all gone. Once this happens, the water drains and more eyes will appear. Stack a totem of two guys and wait for the eyes to come at you before using the water rod to stun then kill these off with the sword. For the third form, Stack a totem of three and use the gripshot to poke the eye and stun it so a hero can slash at it with the sword. Repeat this process several times until the creature is defeated. Use the gateway now.