Underwater Guard Encounter
History
This is not the first time that humans will attack the Corp of no Breathing.
Even though they are mostly 
30 years ago, a party from a neighboring island sent a team of assassins to eliminate the Corp. They eliminated 3 of a team, but were not able to get any of the masks.
Since then they have spent time training in attacking human opponants underwater, so the team has been trained to oppose the attack of the Local 509.

Their strategy is to use the mobility of their shark mouts to strike at a goup of adventurers that are spread out (slowest first) then move quickly away. They will avoid engaging hand to had and instead rely on their advantages in inititive to attack then swim away. Since the sharks move much faster than the party, they should be able to do so with ease.

In addition, their first attack is always to make a circle around their attackers and use their missle weapons. If their opponents attempt to rush a member of the circle, it will break, all will swim away and regroup withing 3 rounds to attack in the same way.

There is a 20% chance that when the guards are attacked, that unwanted lizard men will wait till the end of the battle, then attack the victors!

The Corp of No Breathing has 3 troops of 7 men who stay underwater for 8 hours at a time. They have had decades to improve their skill and obtain the knowledge to maximize their fighting power. As such, they do not suffer as badly from the water.

Each troop of the Corp are able to signal the other to gather together using a strange bladder-like device filled with water. When the sides of the bladder is squeesed, the escaping water passes over several membranes inside a horn from a large waterbuffalo. It makes a sound like an incredably loud fart. This noise is loud enough to startel a person and travels up to 1 mile away.

The Members of the Corp
The Corp are the elete fighters in the city. They are commonly taken from members of the city militia or guards at a young age. Once impressed, they are trained for a minimum of 8 years. This training is a combination of traditional training and practical experience. The training is done by furloughed members of the Corp, or those that have retired from the Corp and are still strong. The practical experience is generally active duty in the city guard where they are assigned to all the "hot spot" places in the city. If there is an attack on the city (which there hasn't been for a long time) they will be in the front lines.
As a result, the Corp ranges from 5th to 8th level in fighter class. A typical party will be:
1- 8th
2- 7th
2- 6th
2- 5th
Each has a 10% chance each to have a score of 18 in St. or Con.

When they are at last ready to join the Corp, they have the skills:
Swiming Proficiency (2 slots)
Underwater Combat
Weapon Specialization for underwater crossbows
Weapon Proficiency in Short Sword, Dagger
Sea Mounted Combat
Ride Water Steed
Underwater Survival
Underwater Communication (talk with hands and distinctive noises within "ID" range of sight.
One per party also has Lizard man language skill

Sharks, Common (12):
These sharks are trained from berth to be either steeds or guards for the Corp.
The steeds have saddles with sturrips that have a cinch on both sides that keep the rider firmly in his seat even when descending at a high rate of speed. The saddle is mounted just in front of the dorsal fin. There is a quick release rein that frees the rider when pulled. The other two reins are attached to metal rings that pass through the cartalidge around the sharks ear holes. Left and right and stop and go faster are performed as on a horse. To go down, the legs are raised up in the stirrups and to go up, the riders stands up in the stirrups.
The guards ring the steeds and respond to hand signals directing them to search or attack the indicated target.

Int Non; AL N; AC 6; MV Sw 24;
The less powerful sharks function as attack dogs, moving pack-like until directed at a target when they move and attack it at maximum ferocity.
             Damage  THAC0
3-4 HD: 1d4+1   17 - A 13        B 10
5-6 HD: 2d4       15 - C 25        D 29
The more powerful sharks are the steeds of the Corp of No Breathing.
7-8 HD: 3d4       13 - E 50        F 43      G 34         H 44       I 32          J 50       K 29      
#AT 1; Dmg 2-5, 2-8, or 3-12; SZ M; ML 10;