Diving on your period — the honest answer
Yes, you can dive on your period. There's no scientific evidence sharks are attracted to menstrual blood. Tampons and menstrual cups (Diva Cup, Saalt) work fine underwater — empty between dives. Some divers find cramps worse with cold water; ibuprofen helps. The only real issue: heavy flow + slow boat = annoying laundry.
Birth control & DCS risk
Combined oral contraceptives (with oestrogen) slightly increase clotting risk, which theoretically increases DCS risk. DAN's current position: no proven link, but be conservative — extra hydration, slower ascents, longer safety stops. Progestin-only pills, IUDs, and implants have no proven DCS impact.
Pregnancy: the absolute no
Diving while pregnant is NOT recommended at any stage. The foetus has no way to off-gas nitrogen — bubbles can form in unborn tissue. There's no 'safe' depth or duration. If you're trying to conceive or might be pregnant, stop diving. Resume 6+ weeks postpartum (longer if breastfeeding and no medical clearance).
Breast implants underwater
Saline and silicone implants compress and expand normally with depth — no risk to the implant or you. The 6-week post-surgery diving ban is for incision healing, not implant safety. After that you're fine, including in cold water. Don't crash into reefs. (Good advice anyway.)
Menopause & diving
No specific contraindications. Hot flashes underwater can be jarring (literally). Hormone Replacement Therapy with oestrogen has the same theoretical clot risk as combined birth control — discuss with a dive doctor if you're starting HRT and dive often. Most women over 50 dive without issue for decades.
Liveaboard practical tips for women
Pack 2× the menstrual products you think you'll need (boats run out). Bring spare bras (sun, salt, and constant wetsuit pressure destroy underwires). Sunscreen for face — reef-safe mineral, not chemical, especially around eyes. Long-sleeve rashguards prevent sunburn AND show less salt staining than swimsuits. Hair tie + small bottle of leave-in conditioner = sanity saver.