Heerema deep-sea rescue divers attacked by a hammerhead shark

The Heerema deep-sea rescue divers attacked by a hammerhead shark is the turning point at which a hazardous cleanup operation off La Palma becomes a direct confrontation with intelligent predators. Gerhard Bohrmann and Stanley Frost descend in pressure suits to free a trapped tube and clear the worm-covered terrace; instead, they encounter sharks that defeat their deterrent, kill Frost, and pursue Bohrmann into a rock crevice. The assault ultimately exposes its purpose: the animals are trying to prevent the humans from removing the worms.

The blocked tube and the decision to dive

The immediate problem is mechanical. The tube’s propellers cannot turn, and the obstruction is too firmly wedged for the team to free it from the surface. Bohrmann first proposes sending down an ROV to shift the debris. Stanley Frost objects that this would take too long, and Jan van Maarten is asked to ready Rambo, a smaller, industry-used vehicle modeled on Victor. It can work at depths of up to eight hundred metres and is equipped with four cameras, stern and side thrusters, and two articulated arms.

Rambo is ready within fifteen minutes and descends on its electro-optical tether along the volcano’s flank toward the terrace. Its cameras confirm that the propellers and video system remain intact, but the tube is jammed. The robot begins lifting rocks one by one, then reaches the critical obstruction: a sharp lava splinter driven into the sediment, pressing the tube against a ledge. Its arms can twist and pull, but cannot generate enough momentum to dislodge the piece. The machine’s limits prompt a riskier human intervention.

Frost volunteers to dive, arguing that the pressure suits can withstand the four-hundred-metre depth and that if Rambo cannot free the tube, the divers must try. At the Heerema station, the suits appear as silver, articulated body pods suspended in a steel container. Each has a helmet with dome ports, segmented limbs, manipulators, and oxygen tanks mounted behind an entry flap. Once suited up, Frost and Bohrmann communicate by wireless rather than hand signals, and Bohrmann tests the manipulators by moving his fingers inside the pod. The technological preparation makes the descent possible, but it cannot make the divers invulnerable.

Clearing the terrace

At the work site, Frost identifies a nearly spherical piece of lava blocking a propeller’s swivel joint. The divers push and shove until the rock comes loose, freeing the propeller. The effort also crushes hundreds of worms on the terrace, making the operation’s environmental and scientific stakes tangible: clearing the machinery means disturbing the organisms the team has come to remove.

The freed propellers stir up silt and reduce visibility. Bohrmann calls for the thrusters to stop when their movement only throws mud into their eyes. As the suspended sediment begins to disperse, he and Frost turn to the larger obstruction holding the tube in place. Frost takes two small charges from a flat box on his exosuit and proposes placing one at the base of the rock, where its tip is embedded in the terrace. Bohrmann recognizes that blasting it carries a risk, but the plan is to use a small charge to break the rock’s support rather than continue an ineffective attempt to shift it by hand.

Before they can proceed, a blue-violet halo appears around the lighting scaffold. The underwater distances are difficult to judge, and the floodlights make it harder for Bohrmann to see clearly, but he detects flashes beyond the scaffold’s lights. The glow fades; Frost remains focused on the structure and warns against acting hastily. Two long shadows patrol the frame, their blue undersides briefly visible before they disappear. The sequence delays the attack just long enough for the divers to glimpse the presence around them without understanding its scale.

The deterrent fails

Two torpedo-shaped animals then rush from behind the scaffold toward the divers. Bohrmann reacts by pushing backward and shielding his helmet, while Frost assures him that the creatures cannot reach them. He explains that the suits carry PODs, or Protective Ocean Devices: electromagnetic deterrents intended to keep sharks at least five metres away. In earlier trials, bait had attracted white and tiger sharks, but activation of the field had prevented them from crossing it. Frost attributes the effect to sharks’ sensitive electro-receptive organs and the field’s disruption of their nervous systems.

That confidence proves misplaced. The two smaller sharks have already come closer than the expected protective distance, and a great hammerhead makes a forceful rush at Frost. It strikes him with its flank after entering the field. The scene establishes that the POD is no longer a reliable boundary, whether because the sharks can overcome it or because their behavior exceeds what the earlier trials anticipated. Frost’s equipment, designed to keep danger at a distance, cannot guarantee control over what happens next.

A much larger hammerhead appears over the scaffold. Its head and body dwarf those of the other sharks, and it seizes Frost’s right arm. As Frost struggles, the shark tears the arm away from the exosuit and bites into the exposed limb, leaving the suit unable to protect him. His oxygen system is compromised, and he dies in the water. The smaller sharks then turn to his body. Van Maarten, watching and communicating from the surface, is also heard shouting amid the confusion.

Bohrmann’s escape and the purpose of the attack

Bohrmann must act while Frost’s suit and the smaller sharks draw attention near the scaffold. He uses the console to start the tracked robot’s propeller, carefully avoiding the homing function that would send him toward the Heerema and into the sharks’ path. The vehicle moves too slowly to offer a quick escape. He instead kicks toward the lava flank, seeking the protection that a rock wall can provide. From there he sees the smaller sharks occupied near Frost, but the largest animal is missing.

The giant hammerhead attacks Bohrmann, drives him against the flank, and returns for another assault. His suit withstands the blows only temporarily. He reaches a crevice in the lava and forces himself inside despite the bulk of the exosuit and oxygen tanks. The shark’s head cannot fit through the opening; it strikes the rock and withdraws before trying again. When Bohrmann’s floodlight comes on, he discovers that the crevice opens into a larger cave and that the shark has become stuck partway inside. He pushes against its head until it retreats. The narrow rock passage, not the suit’s electromagnetic protection, is what gives him a chance to survive.

Van Maarten reports that many more sharks are present and that they are smashing the floodlights. Bohrmann concludes that the attack is intended to stop the team from cleaning up the worms. He rejects an immediate rescue attempt, warning that the divers would face intelligent predators and that sending two people with a decoy would achieve nothing. With oxygen enough for two days, he tells van Maarten to abandon the operation for the moment and keep watch. Bohrmann cannot say that he is safe: the sharks are not behaving like ordinary animals, and their resourcefulness makes the cave only a temporary refuge.

Significance

The incident joins the practical and the strategic. At first, the conflict appears to concern a disabled tube, jammed propeller, and difficult debris; the encounter reveals that the machinery is only one part of the problem. The worms are being reclaimed by the terrace, the divers are trying to remove them, and the sharks’ attack and destruction of the lights interrupt that work. Bohrmann’s conclusion that they are defending the worms reframes the assault as purposeful resistance to human intervention.

The sequence also overturns the assumption that technical safeguards can contain an unfamiliar threat. Rambo can inspect the obstruction but cannot supply the force required to remove it; the pressure suits permit a human dive but leave their wearers dependent on life-support systems; and the PODs, previously tested against other sharks, fail to keep these attackers at a distance. Frost dies despite the protective apparatus, while Bohrmann survives by finding a crevice and refusing a rescue that would expose more divers. The episode therefore makes the human operation’s limits concrete: the team can bring advanced equipment to the seafloor, but it does not control the animals, the terrain, or the consequences of clearing the worms.