Unable to snorkel and dive:
http://forum.thesims3.com/jforum/posts/list/688918.page
edit: removing mods allowed these actions *updated 13/06/24*
Also simmers should try further out from objects in order to snorkel. Just as some frozen ponds cannot be skated on, it may very well depend on where you choose to snorkel. This is not necessarily a glitch.
http://forum.thesims3.com/jforum/posts/list/689268.page
*updated 13/06/25*
Using arrow keys causes landscape items to disappear(unsubstantiated):
http://forum.thesims3.com/jforum/posts/list/0/690109.page
http://forum.thesims3.com/jforum/posts/list/690012.page
*updated 13/06/26*
LTW Dive Professional: Not making money from selling items.
-> Register as Self-Employed - Scuba Diver(this worked for me)