Frequently asked
questions.

For a healthy adult, in a supervised setting, properly hydrated and fed: no. Acute deprivation of 35-40 hours, on a one-off basis, presents no documented structural risk. You have probably already done it involuntarily, in less supervised conditions (new parent, deadline, long night out). Recovery sleep restores cognitive function within 24 to 48 hours. Crucial distinction: chronic deprivation (sustained, < 6h/night for months) is dangerous. Voluntary, supervised acute deprivation is not. See the science page for sources.

Bipolar disorder or history of it. Epilepsy. Severe cardiovascular disease. Uncontrolled hypertension. Pregnancy. Schizophrenia or psychotic disorders. Unstable diabetes. Medication requiring regular sleep. Under 25, over 65 (unless medical clearance after the interview). A detailed medical questionnaire is sent after the first interview. When in doubt, a physician's opinion is required.

The skipper and Mathieu are trained in first aid. The boat carries all regulatory equipment. Maximum distance to a port stays under 1 hour. In a medical emergency: immediate return and care. No incidents to date, but the protocol exists.

Legitimate question, asked bluntly, so a blunt answer: no, except in extreme circumstances (sudden red-alert weather with no return to port possible — in which case the session would have been cancelled upstream). The maritime risk on a 35-hour coastal sail in high-season Mediterranean, with a state-certified skipper and an ISAF-compliant boat, is statistically lower than a day spent driving in France. Not negligible, but not specific to this experience.

None documented in healthy subjects after a single acute deprivation. The recovery sleep that follows restores cognitive function and sleep pressure. Clinical wake therapy studies (medical use of deprivation) confirm the absence of lasting negative effects on moderate-risk subjects. See the science page.

Yes. The intimate format is designed for this (1 or 2 people, full charter). For the collective format, you can apply together — provided each person passes the interview individually. No couple package, no duo pricing in collective. The filter is individual, the experience is collective.

Profiles selected through individual interview. The cohort is coherent: entrepreneurs, executives, creators, athletes, profiles in real inquiry. No spiritual tourists, no thrill-seekers. The human filter guarantees the level of the group, because one misaligned person can compromise the experience for the other 4.

No. There are proposed silent phases (notably 2 hours at H+26), but no enforced silence across the 35 hours. Mathieu speaks when he needs to. So can you, when you need to. Speech is simply rarer and more precise than on land.

Private charter of a sailing boat, state-certified professional skipper, dedicated team (skipper, assistant, Mathieu), individual support across 35 hours non-stop, 15 days of preparation, follow-up, meals, integration. The positioning — from €2,500 for collective, €8,500 for intimate, on quote for bespoke — reflects the rarity of the format and the depth of the support.

30% deposit at booking (to secure the spot after the interview is approved), balance at D-15. Additional instalments possible on request during the interview.

More than 30 days before boarding: full refund minus administrative fees (€50). Between 30 and 15 days: 50% refunded. Less than 15 days: non-refundable, but transfer possible to a later session within the year. Documented force majeure (bereavement, hospitalisation): case-by-case review, commercial flexibility is the norm.

A professional invoice can be issued. Deductibility depends on your status and on how your accountant qualifies the experience. It is neither a certified training nor a classic corporate seminar. Most participants pay personally.