What are the functions for the dive boogie board attachments?

Hi, 

I was looking at the page teaching people how to construct a boogie dive board:

http://
abaloneten.googlepages.com/diveboard-float

Some of the functions are not readily apparent.  Like for example, the cleat on top, does it have another function other than hanging fins?

I'm wondering if someone can briefly introduce the function of each part, or just describe what jobs a dive board must be able to do.  Thanks.

Pretty sure the cleat is not specific to one function, cleat coould be used to tie off any gear bags or fish stringer, tie off point for a kelp clip etc....just an object anchored to the board you can attach stuff to.  Also looks like a nice solid object placed in the perfect spot to whack you in the chops if you get hit by whitewash and the board blows back at you.