Alcatraz Swim 2025

17 May 2025 - 21 May 2025 San Francisco

This event is now SOLD OUT! Thank you so much for your interest in Velindre’s first ever Overseas Swim. If you would like to join our reserve list, please email

Swimming from Alcatraz is one of the most famous open water swims in the world.

The magnificent backdrop of the iconic Gold Gate Bridge and the dramatic San Francisco skyline make Alcatraz an unforgettable swimming experience.

Add to this, being part of a select team of 25 swimmers led by Velindre Charity Ambassador Dave Tonge and Patron Shane Williams, raising vital funds for Velindre, and you have a very special, once in a lifetime event.

The Alcatraz Swim is an approximately 2-mile swim from Alcatraz Island to the St. Francis Yacht Club in San Francisco. Occasionally the swim will go to San Francisco’s Ferry Building, which takes swimmers east instead of west, but is comparable in terms of difficulty.

*Please note: dates are subject to change due as the flights are not out yet*

This challenge is for strong and experienced swimmers only. Before taking on Alcatraz, you should have completed an Ironman distance swim or equivalent. The Alcatraz Swim distance is 3200m meters which is 128 lengths of a 25m swimming pool. 

The Alcatraz Swim should not be your first open water swim!

We would love you to be a part of this elite team of swimmers and join us for Velindre’s first ever overseas swim!

All applicants will be contacted by Dave Tonge by phone to discuss details of the application, your experience and training plans.

If successful, applicants will be required to pay a *£200 deposit to Velindre to secure your place in the event, flight and accommodation and commit to raising a minimum of £3000 in sponsorship for Velindre which will fund research, care and support services for cancer patients and their families in Wales.

Successful applicants will also be required to pay an event entry fee of $295 direct to the event organiser and complete the required event entry forms.

*Deposits are non-refundable and will go towards your fundraising target


17 May 2025 - 21 May 2025


San Francisco

Mae fersiwn Gymraeg y wefan hon wrthi'n cael ei hadeiladu ar hyn o bryd. Yn y cyfamser, os oes angen unrhyw gymorth neu gwybodaeth codi arian arnoch drwy gyfrwng y Gymraeg, cysylltwch â 029 2031 6211 neu

The welsh language version of this website is currently under construction. In the meantime, if you require any information or fundraising support through the medium of Welsh, please contact 029 2031 6211 or email