A night dive off Kona, Hawaii, with manta rays. Big Bertha, measuring 14 feet, one of the largest and oldest in the area, can be seen about 40 sec in. She has been observed feeding in this spot for over 20 years, and now a couple of her offspring come in as well.

The manta rays come to feed on the plankton attracted by the lights set on the ocean floor. The plankton is seen as red little dots in front of the lights.

Duration : 0:5:38