WHOI at a Glance WHOI History Oceanographic Research WHOI Facilities Publications Visitor Information GiftShop What’s New? WHOI Through the Lens Archived Front Page Stories FAQs Contact WHOI	Four Decades of Alvin « Previous  Next » Alvin has gone through a major overhaul about every three years to upgrade various components and check safety systems. All of the sub's components have been replaced at least once, so that none of the original Alvin remains. (©Terri Corbett, Woods Hole Oceanographic Institution)