The following weapons were used in the film Aquaman:
One of the pirates is armed with a Glock 17.
2nd Generation Glock 17 - 9x19mm
Ithaca 37 "Stakeout"
An Ithaca 37 "Stakeout" short-barreled shotgun is used by one of David Kane's pirates.
Ithaca 37 "Stakeout" parkerized finish with synthetic forend - 12 Gauge
A pirate holds his shotgun.
Colt Model 933
Colt Model 933 carbines are used by Jesse Kane (Michael Beach) and David Kane's pirates who infiltrate a Russian nuclear submarine.
Colt Model 933 with Surefire M900 weaponlight foregrip and M68 Aimpoint scope - 5.56x45mm
A pirate with his Model 933.
Two pirates with their Model 933 carbines.
David Kane (Yahya Abdul-Mateen II) uses an F-88A1C Austeyr carbine.
F-88A1C Austeyr - 5.56x45mm
M203 Grenade Launcher
One of the pirates is armed with a Model 933 fitted with an M203 grenade launcher. Judging by how it's mounted, it's likely an airsoft model. A similar configuration is used by Jesse Kane (Michael Beach).
M203 grenade launcher made by G&P - (fake) 40x46mm. Note the RIS mount and removed trigger guard.
An M203 grenade launcher is seen.