Tentalus is the boss of the Sandship - the fifth dungeon in The Legend of Zelda: Skyward Sword.
To reach this boss, you must first venture across the deck and hull of the Sandship, using the Wooden Bow to shift time back and forth.
Make sure your quiver is full of arrows before the battle, because you're going to need them!
Our Tentalus boss strategy will help you defeat this sea monster, so you can reach the Fire Sanctuary, the game's sixth dungeon, which sits at the summit of Eldin Volcano.
If you'd like to learn more, visit our Skyward Sword walkthrough.
Tentalus boss battle strategy in Zelda: Skyward Sword explained
The boss battle against Tentalus starts a little differently compared to the others in Skyward Sword, because, before you face the monster, you need to reach the deck of the Sandship first.
Your way, however, will be blocked by the tentacles of Tentalus, which, thankfully, can be knocked out of the way with a Skyward Strike. You will also have to avoid barrels, which, in places, will come running towards you.
Eventually, you'll reach the door to the ship's deck again and, beyond it, face Tentalus in a two staged battle:
The first stage of your battle against Tentalus is the longest and it begins with the creature pushing its tentacles through the deck.
These tentacles will actually chase you, trying to appear beneath Link's feet, so you must keep moving and try to avoid having one either hit you or pick you up.
To defeat these tentacles, you need to hit them with either a horizontal or diagonal Skyward Strike. A vertical Skyward Strike will cause the tentacle to retract, but it won't destroy it.
Eventually, you'll destroy enough tentacles that Tentalus will rise from the sea to attack you by slamming it's two main tentacles down onto the deck towards you. These tentacles can also be destroyed using a Skyward Strike, though Tentalus will regrow them.
You will now have to hit Tentalus in the eye with an arrow using the Wooden Bow.
When you do this successfully, Tentalus will fall to the deck, giving you the chance to attack it's eye with your sword. It's a good idea to start running to the edge of the deck the moment your arrow hits true, so you can get as many swings in as possible.
If you're having some trouble aiming for Tentalus' eye, try destroying one of its tentacles, because this will cause it to stay still for a number of seconds as it regrows it's missing limb.
After you've got some good hits in, Tentalus will return to the sea and start attacking you with tentacles again. These tentacles will appear more frequently and it will also attempt to hit you more frequently once Tentalus is out of water.
Tentacles may also attack you from different sides of the deck, so be wary!
The second stage of your fight against Tentalus begins with the monster attempting to destroy the deck.
To reach some form of safety, you need to climb the nearby crate, while avoiding the falling barrels, to reach the upper level of the deck. Unfortunately, Tentacles will follow you.
Here Tentalus will attack you with its head tentacles, which, fun surprise, have mouths.
You can easily defeat these tentacles with a couple of sword swings and, doing so, will grant you the chance to shoot Tentalus in the eye again.
When done successfully, Tentalus will, again, fall to the deck, allowing you to attack its eye. Now all you have to do is keep repeating this process, until Tentalus dies!
Once Tentalus is finally defeated, collect the Heart Container and complete a Skyward Strike to evolve your Goddess Longsword into the Goddess White Sword.
If you're carrying the Wooden Shield, this is also an excellent time to stop off at Skyloft and which switch it for a less flammable defence method.