Where can I find the jpegs for the Bubble Under website GALLERY page?
Hi Richard_Del . Welcome to the forums. 
Those images are included with the code archive for the book, which you can get at http://www.sitepoint.com/books/html3/code.php
E.g. the divers-circle.jpg file is in /chapter2/website_files/05_clickable_email_and_image/