Shark Man Warrior

ST 18		HP 18
DX 13		Per 11
IQ 10		Will 11
HT 12		FP 12

basic speed 6.5
Move 6 (Water Move 6) 
DR 3 (1 DR, 2 from leather armor) 

Spear (14): 1d6+4 imp   
Club (14): 3d6+1 Cr 
Net (14): Special (See Basic 410) 
Bite (13): 1d+1 Cut 

Dodge: 10
Parry (club): 11
Parry (Spear): 11

Traits: Amphibious, Doesn't Breath (Gills), Combat Reflexes, Nicitating Membrane, Pressure Support 3, Speak Underwater, Night Vision 6, Dependency (Water, Very Common, Daily), Sharp Teeth

Personality Disadvantages: Roll three of Bad Temper(1), Bully(2), Callous(3), Selfish(4), Ugly(5), Chummy(6), Compulsive Carousing(7), Overconfidence(8), Wounded(9), and Intolerance (non-sharkmen) (10)  

Skills: Spear -14, Broadsword -14, Net-14,  Swimming -13, Brawling -13,  Wrestling - 12, Stealth -12, Intimidation -12, carousing -12

A sharkman warrior, based on the racial template from GURPS Banestorm and the Guard template from GURPS Dungeon Fantasy, with an NPC stat block for ease of Use. Their equipment is intentionally low tech: metal won or traded for from the land dwellers is valuable and given to higher status shark men than these. 

These are designed for use as henchmen: their immense size puts them almost in ogre  territory in terms of strength.

Some of them will be armed with spears, some with clubs and nets

The personality disadvantages are optional: in most cases you won't need them, but if you do, its highly unlikely that the army of shark men all have the same disadvantages, even if they have some general trends. But characters looking for weakness will find them, and the adventure that inspired this has at least a little bit of social interaction with the sharks.