A 54-year-old New York woman died after an incident in rough seas off a remote beach in Chilmark on Tuesday afternoon, where she was swimming with two friends.

The accident took place off the south-facing ocean beach on the Chilmark Pond Preserve, a property owned by the Martha's Vineyard Land Bank.

At press time yesterday, police had not yet released the name of the victim, although several officials confirmed she was a summer visitor who lived in a suburb of New York city. The cause of death has also not been confirmed.

Police on Tuesday used two all-terrain vehicles and a four-wheel-drive vehicle to reach to scene of the accident, while one group of emergency medical technicians used a canoe to reach the beach by paddling across Chilmark Pond. The victim's husband reportedly administered CPR while waiting for emergency personnel to arrive.

According to police, an eyewitness called 911 at 12:20 p.m. from the beach using a cell phone, and helped direct emergency responders to the location.

The initial call received by police from the Islandwide emergency dispatch reported that three people were having trouble in the ocean near the land bank property off South Road. As police, fire and emergency medical workers were responding, an update came from dispatch that the three people were out of the water, and that a woman was unconscious with CPR in progress.

When emergency personnel arrived on the scene, the woman was still not breathing, and emergency medical technicians took over administering CPR to the victim.

It is not known whether the woman was pulled underwater by a riptide, or suffered a medical condition while in the water.

Weather conditions on Tuesday were sunny and windy, and seas were rough. The remnants of two tropical storms created high surf with five to ten-foot waves crashing into Lucy Vincent Beach. The tide was midway between high and low at the time of the accident.

Chilmark police chief Timothy Rich on Wednesday said although the cause of the death has yet to be determined, it was possible the victim was caught in a riptide, a strong current that pushes away from the shore as a strong storm nears.

"[Riptides] have been a problem this year, and we see them just about every summer. I know we were seeing the effects of two tropical storms when it occurred, and I know it was rough swimming at the time she became distressed," Chief Rich said.

Mr. Rich said the incident recalled another tragedy in September of 2004 when a 58-year-old Cambridge woman drowned while swimming with a friend at a remote location more than a mile from the town portion of Squibnocket beach. The drowning was attributed to strong riptides linked to Hurricane Frances.

The Chilmark Pond Preserve is an 8.3-acre property that runs from South Road to the Atlantic ocean with Chilmark pond in the middle. The only access to the ocean beach is across the pond.

While the locations were different, Mr. Rich said emergency personnel had difficulties reaching the victim in both instances. Two years ago, it took approximately 15 minutes for rescue workers to reach the beach, largely because the area was inaccessible by traditional rescue vehicles.

Following that incident, the town purchased a special trailer equipped with a rescue apparatus; the trailer can haul someone strapped to a gurney and can be attached to the fire department's all-terrain vehicle.

Fire and medical personnel on Tuesday reached the scene of the accident from Lucy Vincent Beach, and by boat across Chilmark Pond.

When they reached the victim, she was transported approximately two-thirds of the way back to the Lucy Vincent parking lot before she was transferred to a four-wheel drive vehicle owned by Oak Bluffs and equipped for emergency medical response at the paramedic level.

Mr. Rich said initially the ATV had to drive slowly so emergency personnel could walk alongside the trailer to perform CPR.

After arriving at the Lucy Vincent parking lot, the victim was transferred to a waiting Tri-Town ambulance and taken to the Martha's Vineyard Hospital, where she was later pronounced dead.

Chief Rich said there are many difficulties in responding to emergencies in remote beach locations. Even with a four-wheel-drive vehicle or ATV, rescue workers must negotiate tides and large rocks.

"Considering the location, the rescue workers did an excellent job getting there as quickly as they did," the chief said.