Fishman Karate is a martial art that is practiced by certain skilled members of the fishmen race. While deadly enough on land, Fishman Karate has a number of devastating underwater moves designed to be suitable with the Fishmen strength and speed along with the mobility that goes while underwater and, in some cases, a fishman's personal adaptation (fins, teeth, etc.).
According to Jimbei, the secret of Fishman Karate is mastery of the water in the user's direct vicinity, using its power to send powerful waves impacting the water within the opponent's body. Since every living creature is nothing more than a mass of water, the users of Fishman Karate are able to battle opponents that are usually highly resistant (if not immune) against blows and punches. This was demonstrated against Monkey D. Luffy, a rubber man, who is nearly immune to blunt attacks.
Jimbei also displayed that Fishman Karate can be used effectively on land as he can utilize the water in the atmosphere and make use of it to attack.
This martial art can be learned on Fishman Island, more specifically at the Fishman Karate Dojo.
- Arabesque Brick Fist: Jimbei punches at a fair distance from the intended target(s), so instead of the fist connecting, it uses the water vapor in the air to release a shock wave that sends them flying. This move has a delayed effect, as the shock wave takes a while to affect the opponent(s).
- 5,000 Brick Fist: A stronger version of the Arabesque Brick Fist. It is used like an uppercut, rather than a straight punch, sending the opponent flying skywards.
- Spear Wave: A technique used on a body of water's surface. Jimbei heaves a spear-shaped burst of water with enough force to punch a hole in solid structures.
- Sharkskin Palm Thrust: A simple palm block with enough force behind it to block stuff.
- Shark Brick Fist: A powerful straight punch that is strong enough to send the opponent reeling.
- Water Shot: Jimbei hurls a simple droplet of water at his opponent, which can become a deadly bullet with the kinetic force created by his immense fishman strength.
- 7,000 Brick Roundhouse Kick: Jimbei performs a very strong roundhouse kick.
- Vagabond Drill: The most powerful technique of Fishman Karate, Jimbei hurls a pack of water in his hands and shoots a powerful water shock wave that pierces through his opponent's body.
Hody Jones has shown extreme power with his Fishman Karate, so much that Usopp claimed that he was above Arlong; this mighty strength has further been boosted by Hody's overdose on the Energy Steroid drugs. However, Jinbe regarded Hody as a novice compared to himself. Despite Hody's power, his Fishman Karate is shown to be at an amateur level in comparison to Jimbei's as he was unable to do any damage to Luffy causing the rubber man to even comment that Hody's level was inferior to Jimbei's. Additionally much of Hody's power was a result of his use of Energy Steroids. He could no longer use these moves as he overdosed on Energy Steroids, which eventually stripped him of all of his natural prowess, rendering him a frail and weak old man, and the fact that he was arrested and put in the prison of the Ryugu Palace.
- Shark Grip: Hody uses his tremendous strength and grip to crush large walls of stone.
- Shark Arrows: Hody first wets his arm, then he uses his massive strength to throw many drops of water, which are converted into deadly arrows through mere kinetic force. After his transformation on Energy Steroids, Hody secretes the water from his arm, rather than gathering it from an external source.
- Water Shot: The basic version of Shark Arrows, in which Hody throws a single drop of water like a bullet. After undergoing the transformation due to the Energy Steroids, the penetrative force of this attack has increased in an unbelievable way, to the point where it not only pierced through a fishman, but also through several structures and rock formations behind him, moving a long distance away from the location from which it was fired, and only then returning to its original state of drop and falling in the water.
- Sea Drums: Hody punches the water in front of him pushing it at his opponent and sending a shockwave through it. The shockwave hits the opponent dealing great damage and leaving a pressure mark on his body.
- This fighting style seems to go by a ranking system not unlike that of standard karate that measures a practitioner's level of expertise in relation to the rank they achieved.