Two siblings swam for more than half a day, battling huge waves and fearing sharks after their fishing vessel capsized.

Dan Suski, 30, of San Francisco, and his sister Kate Suski, 39, of Seattle, chartered a boat last Sunday and had planned for a day of fishing in the waters off St. Lucia. A captain and first mate also came along for the excursion.

The 31-foot fishing vessel suddenly took on water Sunday afternoon, forcing all four people on board to strap on their life jackets and jump into the open water.

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"It was completely surreal watching the boat stern go down, go subsurface underwater was surreal," Dan said.

In the chaos of it all, the Suskis were separated from their crew by the swelling sea. They said they saw a beacon of hope in the distance, dry land, and started swimming toward it.

"It would disappear intermittently as we swam but we felt the wind behind us and used that as a gauge for direction," Kate said.

After a grueling 14 hour swim and battling hypothermia, the Suskis made it to shore.

The pair said they spent the night eating bananas and mangoes. The next day they hiked until they found a farm worker who alerted authorities.

""We were very lucky we found a small sliver of beach and we were able to get to safety that way," Kate said.

The Suskis were hospitalized and treated for dehydration and various injuries. The captain and first mate were in the water for nearly a day before a private boat owner plucked them to safety.

St. Lucia's maritime affairs unit is investigating the cause of the shipwreck.