Kansas man charged with attempted murder after Hawaii snorkel tour stabbing

Suspect Avery Nissen allegedly attacked the boat's 62-year-old captain with a filet knife during the tour off the Kona coast.

Apr. 18, 2026 at 7:43pm

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An extreme close-up of a filet knife, its sharp edges and serrated blade dramatically illuminated by a harsh flash against a dark backdrop, conveying the gritty, investigative nature of this crime story.A violent attack on a Hawaii snorkel tour boat exposes vulnerabilities in tourist safety protocols.Overland Park Today

A 21-year-old man from Overland Park, Kansas has been arrested and charged with attempted murder, first-degree assault, and second-degree assault after allegedly stabbing the captain of a snorkel tour boat off the Kona coast of Hawaii. The incident occurred on Thursday afternoon when the boat was returning to the Honokohau Harbor.

Why it matters

Violent crimes against tourists are rare but concerning incidents in Hawaii, which relies heavily on the hospitality industry. This attack on a snorkel tour raises questions about safety protocols and security measures for water-based activities popular with visitors to the islands.

The details

According to police, Avery Nissen allegedly attacked the 62-year-old male boat captain with a filet knife while the three-hour snorkel tour was underway. Other passengers on the catamaran vessel intervened and restrained Nissen. The victim sustained a stab wound to the lower abdomen and numerous cuts to the head and hands, but was transported to the hospital in stable condition.

  • The incident occurred at 3:21 p.m. on Thursday, April 17, 2026.
  • Nissen was charged on Friday, April 18, 2026.

The players

Avery Nissen

A 21-year-old man from Overland Park, Kansas who has been charged with attempted murder, first-degree assault, and second-degree assault for the alleged stabbing attack.

The boat captain

A 62-year-old male who was the captain of the catamaran snorkel tour boat and sustained a stab wound and cuts during the attack.

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What they’re saying

“Police ask anyone with information about this incident is asked to contact Detective Bradley Llanes at (808) 326-4646, ext. 268 or via email at Bradley.Llanes@hawaiipolice.”

— Detective Bradley Llanes, Detective

What’s next

Nissen's initial court appearance is scheduled for Monday in Kona District Court. The judge will determine if he should be granted bail.

The takeaway

This violent attack on a tourist activity highlights the need for heightened safety protocols and security measures for water-based excursions in Hawaii to protect both visitors and operators from potential harm.