Starring Zhao Yixin, Li Jiayi, Qiu Shijian, Jiang Yan-Xi, Emir and Waise Lee, written by Wu Yang, Ma Huai-Chang and Dina Hamiti. Directed by Wu Yang for Culture Media Co/Rabbit Hole Film.

A research complex on a remote island, used for genetic experiments on snakes by a company called the Carsi Group, is forcefully shut down by its owner (Waise Lee), who even allows his soldiers to mercilessly gun down the scientists (as also happens in the Chinese monster-actioner NO WAY TO ESCAPE), but (surprise, surprise) some of the scaly lab-modified creatures survive…

Featuring what is probably the most beloved type of monster used in this recent wave of Chinese creature features – a massive snake beast – the film begins on the island, switches to a cruise ship location for the movie’s midsection, then returns to the island for the finale.

After multitudes of the normal-sized, aggressive lab snakes, plus a much larger serpent, crawl up onto the ship we are treated to lots of snakes-on-a-cruise-ship hijinks, as a motley bunch of survivors, led by no-nonsense hero Qin (Yixin), dash about the corridors to avoid the slithering killers. Adding to the danger is the truly massive, crested, mutant snake that rises from the sea and wraps itself around the doomed vessel.

Qin and those who’ve managed to avoid the venomous reptiles escape the ship on an inflatable life raft that drifts to the island from which the savage serpents had originated. Here the plot becomes even more monster-tastic, as the characters encounter different types of killer creatures that’ve mutated thanks to the leakage of chemicals from the abandoned labs. My favourite new critters are giant barnacles that cluster along the shoreline. These can extend long, fleshy, prehensile mouthparts to chow down on victims!

Another monster that’s encountered is a massive, stilt-legged spider that lurks in the tree canopy and is definitely a rip off of the very, very similar bamboo forest arachnid seen in KONG: SKULL ISLAND (2017).

Zhao Yixin plays Qin as a very committed, serious dude on a mission, though he does get to have a sad, reflective moment as he recalls his dead love, who had died earlier investigating the Carsi Group. Qin and the few survivors are, of course, threatened yet again by the mega-snake, but they devise a plan that ends with the snake falling off a cliff and getting chewed to death by the berserk barnacles!

Despite a misleading title (the mutant snake comes from an island, not the deep sea) and colourful promo illustrations that suggest the lead character will be some kind of gun-toting, super-fighter femme fatale (even though that particular character is killed off near the start of the tale), DEEP SEA MUTANT SNAKE is still a perfectly fine example of the typical sort of Chinese monster movie currently being created.

One more look at those cool mutant barnacles…