MONTEREY, Calif. (AP) — The Coast Guard was searching with vessels and aircraft Monday for four family members, including two children under 8, who reported that they were forced to abandon their sailboat because it was sinking south of San Francisco.

The group was approximately 65 miles off Monterey around 4:20 p.m. Sunday when they made a distress call, Coast Guard Lt. Heather Lampert said. Their location initially was reported farther north, but Lampert said investigators using the boat's radio signal and radar now believe the call came in west of Monterey Bay, which is about 100 miles south of San Francisco. The boat did not have a working GPS system.

The boaters said their 29-foot sailboat was taking on water and their electronics were failing.

An hour later, the group reported it was forced to abandon the boat. They didn't have life rafts, so they were trying to make one out of a cooler and life preserver ring, Lampert said.

The Coast Guard then lost radio contact with the group. The Coast Guard has not identified the family, although investigators were able to determine from the broken distress calls that they were a husband and wife, their 4-year-old son and his cousin, Lampert said. The agency has received no missing persons' reports.

The National Weather Service had issued an advisory throughout the weekend warning boaters of strong winds and rough seas around the San Francisco Bay Area.

Mariners "operating smaller vessels should avoid navigating in these conditions," the advisory said.

Lampert said Coast Guard crews searched through the night. A California Air National Guard helicopter was assisting with the effort.