We wanted to do the whole kayaking/whale watching thing while in Maui but thought $100/per person was a bit much (considering all the other stuff we were doing!)  So instead, we rented a double kayak at the Five Palms Hotel for around $30 and headed out on an adventure of our own.  So glad we did!  We paddled way the heck out there, attempting to catch up to the various whales we saw in the far distance, when suddenly we heard the most absurd sound.  It was creepy and amazing all at once.  It sounded like we were surrounded by a bunch of mammals talking to each other under the water.  Then we saw a large puff of water (assuming from the blow hole) and a whale surfaced right in front of our kayak!  Incredible, just incredible.