Tsushima Katsugi Breath-Hold Diving: Research Summary

By Rubicon Foundation editorial team

5 min read · 4 November 2026

Diving pattern of Tsushima male breath-hold divers (Katsugi) is a 1985 journal article by Shiraki K, Konda N, Sagawa S, Park YS, Komatsu T and Hong SK. Its subject is how male Katsugi divers from Tsushima dive while holding their breath—a question relevant to underwater physiology, work practices and diving medicine.

What does a breath-hold dive pattern describe?

A dive pattern is the sequence and timing of underwater activity: how a diver descends, works or moves below the surface, returns, and recovers before the next dive. The pattern matters because a breath-hold dive is not an isolated event when dives are repeated. Surface intervals and the demands of the task shape the physiological load across a working session.

Katsugi identifies the particular diving practice named in the article title. Studying a named local practice places physiology in its working context: the diver’s activity, the underwater task and the rhythm of repeated exposure can all matter when interpreting what happens to the body.

Why does breath-hold diving affect the body?

Before submersion, a breath-hold diver has a finite store of oxygen in the lungs, blood and tissues. During the dive, oxygen continues to be used while carbon dioxide accumulates. The balance changes with exertion, depth, duration and individual physiology; the body’s responses to immersion and pressure also influence the experience of the dive.

Ascent and recovery are important parts of the sequence, not simply pauses between descents. A diver may feel able to continue while oxygen availability is falling, and a loss of consciousness can occur around the end of a breath-hold dive. Repeated dives make the timing and quality of recovery especially relevant to safety and physiological interpretation.

Which concepts help interpret a dive sequence?

Several connected factors guide the study of breath-hold diving. They help distinguish the demands of an individual submersion from those that build across repeated dives:

Apnoea: a period without breathing, including the time spent underwater on a breath-hold dive.
Immersion and pressure: water and depth alter the conditions under which the respiratory and circulatory systems operate.
Workload: swimming, collecting or other underwater tasks use oxygen and can change the physiological cost of a dive.
Surface recovery: breathing and resting between dives support recovery, while the length and pattern of these intervals affect repeated exposure.
Hypoxia: inadequate oxygen supply to tissues, a central hazard of prolonged or strenuous breath-holding.

These concepts interact rather than acting independently. A dive pattern therefore provides a framework for asking how task, submersion and recovery fit together, without treating a single depth or duration as a complete account of physiological stress.

How does this subject fit into diving research?

Research on breath-hold diving connects field observation with human physiology. Describing how divers actually conduct a sequence of dives can help frame questions about oxygen use, recovery, workload and underwater exposure. This approach complements laboratory work, where particular physiological responses can be examined under more controlled conditions.

The subject also has practical relevance beyond one diving tradition. Divers, diving physicians and scientific divers need to consider the full pattern of exposure when assessing breath-hold activity, especially when dives are repeated or involve physical work. The same general principles can inform questions about fatigue, blackout risk and safe supervision, although specific risks depend on the person and circumstances.

What should readers take from the research context?

The article belongs to the literature on human breath-hold diving and the relationship between underwater behaviour and physiological strain. Its subject is useful for readers interested in how diving practices can be described and related to medical questions, rather than reduced to a single performance measure.

For clinical concerns about breath-hold diving, an individual’s health, training and exposure pattern matter. General physiological information cannot replace assessment by a diving-medicine physician, particularly after loss of consciousness, suspected hypoxia or other concerning symptoms.

Frequently asked questions

What is Katsugi?

Katsugi is the breath-hold diving practice named in the article title, associated there with male divers from Tsushima.

Why study the pattern of repeated dives?

The sequence of submersions, underwater work and surface recovery helps describe cumulative physiological demands and the conditions surrounding breath-hold diving.

Which medical issue is central to breath-hold diving?

Hypoxia is a key concern because oxygen is consumed during breath-holding. The risk depends on factors such as exertion, duration and recovery; medical concerns should be discussed with a diving-medicine physician.

Citation details

Title: Diving pattern of Tsushima male breath-hold divers (Katsugi)
Authors: Shiraki K, Konda N, Sagawa S, Park YS, Komatsu T, Hong SK
Year: 1985
Published in: Undersea Biomed Res 12(4)
Identifiers: PMID 3936250
Record type: Journal article
Repository record: Rubicon Research Repository, handle 123456789/3035

This page is an original summary written by the Rubicon editors from the publication’s bibliographic record. It does not reproduce the paper, its abstract or its data; consult the publication itself for its methods and findings.