Time it as HIGH as possible on the return, when you are usually in a rush and have the sun in your eyes, if it's late day...
Just watch that your boat doesn't drift away while the clan is exploring the islands.
You may be referring to birdcrap island, (middle of the bay) or you are simply seeing the outer reef pop up from the water. At low tides, it's like that around most of the bay, with just a couple safe zones to sail through.
It's a good fishing spot. You should head out there with a Hawaiian Kayak Sailing Club member some time, but definitely not the keiki.http://hawaiikayaksailingclub.com/hkscforum/index.php