Volcanoes of the Deep Sea was released in 2003. The film is still exhibited by select IMAX theaters and other giant screen theaters. Check with your local theater for availability, dates and times.
The film is also available on DVD and Blu-ray from leading local and online retailers. Here are some examples:
amazon.com
blu-ray.com
barnesandnoble.com
chapters.indigo.ca
netflix.com
walmart.com
(Links and availability from specific retailers subject to change).