I'm not too sure about the handles in the front, but with regards to the handles at the back, have a look at the HobieCat forum...this link should help (if it opens).

http://www.hobiecat.com/community/viewtopic.php?t=1832&highlight=foot+straps

If it won't open, just enter the forums, and do a search in the hobie 16 section on foot straps.

Hope it helps
clint