# Forty-one military veterans entered a weeklong ocean surf therapy study and the smaller groups who completed paired follow-up surveys still showed lower depression and PTSD scores 30 days later

> Forty-one U.S. military veterans joined a weeklong ocean surf therapy program and among the smaller groups who completed matched surveys, depression and post-traumatic stress scores stayed below starting levels 30 days after the event. The study, published in Frontiers in Psychology, followed...

Canonical URL: https://www.argo.net/forty-one-military-veterans-entered-a-weeklong-ocean-surf-therapy-study-and-the-smaller-groups-who-completed-paired-follow-up-surveys-still-showed-lower-depression-and-ptsd-scores-30-days-later/
Byline: ARGO.net Editorial Team
Published: 2026-08-03T19:55:02+00:00
Categories: News, Oceans

![Four surfers paddling together in the ocean](https://www.argo.net/wp-content/uploads/2026/08/surf_therapy_group_ocean.jpg)

Forty-one U.S. military veterans joined a weeklong ocean surf therapy program and among the smaller groups who completed matched surveys, depression and post-traumatic stress scores stayed below starting levels 30 days after the event.

The study, published in [Frontiers in Psychology](https://www.frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2025.1613418/full), followed veterans taking part in **Operation Surf** events near Avila Beach and Santa Cruz, California. The program mixed **adaptive surfing** with yoga, shared meals, group reflection and peer support, while the research team collected mental health surveys and data from wearable **WHOOP bands**.

The results point to a strong short-term signal, with a careful limit. The study enrolled 41 veterans, but fewer people completed each follow-up survey. The 30-day paired analyses were based on matched responses from 17 veterans for anxiety, 20 for depression and 20 for PTSD symptoms. Because there was no control group, the findings show associations after the program rather than proof that surfing itself caused the score changes.

## A surf week built around more than waves

The participants were veterans with self-reported PTSD who had served after September 11, 2001 and had at least one combat deployment. They ranged in age from 28 to 56, with an average age of 41.6 years. Of the 41 enrolled veterans, 27 were men and 14 were women.

During each six-day event, two days were used for travel and four full days centered on adaptive surfing and wellness activities. Surf sessions took place twice a day, usually for two to three hours, with instructors working one-on-one or one-on-two with participants. The study describes the surf sessions as moderately to vigorously strenuous, depending on ocean conditions and each veteran's fitness.

Morning yoga and stretching aimed to prepare the body and encourage steady breathing. Shared meals and evening reflection sessions gave participants a repeated chance to talk with peers. The researchers noted that no formal psychotherapy was delivered, although informal therapeutic conversations often happened among veterans, instructors and staff.

After the in-person week, participants were invited to stay connected through a private GroupMe chat and optional weekly Zoom meetings. Those follow-up supports are important when reading the 30-day results, since the study tested the full **weeklong surf therapy program** as delivered in practice, rather than surfing alone.

## Scores fell among matched survey completers

The strongest reported changes came from three common self-report tools: GAD-7 for anxiety, PHQ-8 for depression and PCL-5 for PTSD symptoms. These scales ask people to rate recent symptoms, then researchers compare scores across time.

For anxiety, 30 veterans completed the first **GAD-7** survey, while 21 completed it immediately after the event and 21 completed it 30 days later. The paired analysis used only people with matched responses at both points being compared. In that matched group, GAD-7 scores dropped 59 percent immediately after the program and remained 30 percent below baseline at 30 days.

For depression, all 41 veterans agreed to take the **PHQ-8**, but completion was 32 before the event, 22 immediately after and 26 at 30 days. The paired depression analysis used 17 veterans for the immediate post-event comparison and 20 veterans for the 30-day comparison. Among those matched completers, PHQ-8 scores fell 44 percent right after the event and 30 percent at 30 days.

PTSD symptoms followed a similar pattern in the paired **PCL-5** analysis. Before the event, 32 veterans completed the PCL-5. Completion fell to 26 right after the event and 23 at the 30-day mark. The matched analysis reported a 38 percent reduction from baseline to immediately after the event among 22 veterans and a 35 percent reduction from baseline to 30 days among 20 veterans.

The paper also reported clinical threshold changes. Before the event, 25 of 32 PCL-5 completers scored above a selected PTSD symptom threshold. At 30 days, 7 of 23 completers scored above that threshold. The smaller denominator matters because the follow-up group may differ from people who did not complete later surveys.

## Wearables added a body signal

The study also tested whether wearable devices could add useful body-based data to a field study. Thirty-three veterans were contacted for the WHOOP portion and all agreed, although this wearable group was smaller than the survey group because of supply problems with straps.

The researchers focused on **heart rate variability**, deep sleep and REM sleep. Heart rate variability, often shortened to HRV, reflects how much time changes between heartbeats. In general, it can give clues about stress and the body's balance between alertness and recovery, although it cannot diagnose PTSD or depression by itself.

Across all wearable participants with matched data, HRV dropped significantly from before the event to during the program, from a mean of 41.94 to 37.05. The authors did not treat that drop as a simple benefit. Surfing, travel, new routines, social exposure and physical effort could all affect HRV during an intensive week.

Sleep findings were mixed. For all participants, deep sleep showed a small significant drop from during the event to the 30 days after it. Among female participants, deep sleep increased during the event compared with baseline, then fell afterward. Female participants also showed a decrease in REM sleep from during the event to the 30-day period. The study described these sex-specific findings as early signals for future work, since the subgroup counts were small.

## The ocean setting may support attention and trust

Surf therapy combines physical effort, water exposure, coaching and peer contact in a place that feels different from a clinic. The ocean demands attention to waves, balance, breath and timing. For some veterans, that may help pull attention toward the present moment.

The group setting may also be part of the effect. Veterans spent the week eating together, learning in the water, watching daily recap videos and sharing emotional responses. For people living with PTSD symptoms, repeated experiences of trust and shared challenge can support **peer support**, although this study cannot separate the ocean activity from the social design.

The program also fits a wider interest in nature-based care. Earlier research has examined outdoor activity for mental health, including surf and hike therapy for service members. [San Diego State University](https://www.sdsu.edu/news/2025/10/surfing-eases-symptoms-of-ptsd) described the work as evidence that surfing combined with other support can be studied as a non-medicinal approach for PTSD symptoms.

The tools used in the study also matter. Self-report surveys tell researchers how people describe their own symptoms. Wearables add continuous data from daily life, which can show patterns around sleep and body stress. In this project, the wearable data supported feasibility more than firm clinical conclusions.

## Why the study stops short of proof

The clearest caution is the **lack of a control group**. Without a group of similar veterans who did not take part in the program, researchers cannot know how much of the change came from the intervention, normal symptom movement, expectation, time with peers, other care, or the kind of people who completed follow-up.

The study also used a convenience sample from veterans already attending Operation Surf events. PTSD diagnosis was self-reported in the program application process and was not independently verified by the research team. Other details, including education, employment, disability rating, treatment history, medication use and substance use, were not systematically collected.

Follow-up completion is another limit. People who felt better, felt more connected to the program, or were more comfortable with surveys may have been more likely to respond 30 days later. The authors noted the risk of survivorship bias, which can make improvements look larger if non-responders had less benefit.

The PCL-5 timing adds one more wrinkle. The PTSD survey asks about symptoms over the past month. The immediate post-program PCL-5 could include symptoms from before and during the surf week, while the 30-day survey better reflects the month after the intervention. That timing makes the 30-day PTSD comparison especially important and it also shows why exact time points matter.

## Next trials need stronger comparisons

The study's best use may be as a roadmap for larger research. A randomized trial could compare surf therapy with another active program, usual care, or a waitlist design. Longer follow-up could show whether symptom changes fade, hold steady, or grow with continued peer support.

Future studies could also test the parts of the program separately. Surfing, yoga, social meals, evening reflection and online contact may each play a role. A larger design could ask whether the water activity has a special effect, whether group connection carries most of the benefit, or whether the mix works best as a whole.

Researchers also need better baseline detail. Medication, current therapy, sleep problems, disability rating and prior surf experience could all affect outcomes. More complete background information would help explain who may benefit most and who may need a different form of support.

For now, the findings give a cautious signal. Among veterans who completed matched surveys, depression and PTSD scores were still lower 30 days after a week centered on adaptive surfing and peer support. The next step is to test that signal with stronger study designs that can separate hope from evidence.