The group was on a catamaran with Capt. Dave's Dolphin & Whale Watching Safari when they spotted the basking sharks only two miles from shore.
The sharks, which are filter feeders, were skimming the surface of the ocean looking for plankton to eat. The sightseers captured video of the sharks feeding. One appeared to be more than 20-feet long, while the other appeared slightly shorter.
Sightings of basking sharks, known as the second-largest shark species, are rare, according to Capt. Dave's. The company's records indicate basking sharks were spotted once in 2012 and 2013.
Adult basking sharks can reach up to 30 feet and weigh more than 5 tons. The species is classified as a species of concern by the National Oceanic and Atmospheric Administration. There are estimated to be about 300 to 500 basking sharks left in the eastern North Pacific. Fisheries and eradication programs have impacted the population.