ELMONT - Underwater mortgages are becoming a troubling trend across Long Island.

National data provider Core Logic found 9.9 percent, or almost 54,000 Long Island homeowners, are dealing with underwater mortgages. That means they owe more on their mortgages than their homes are worth.

The Long Island Housing Partnership says homeowners with underwater mortgages are in a bind. They must either stay and pay the mortgages or sell their homes for less. The only hope they have is to appeal to the lender for a loan modification, which is a long shot.

Experts say it's not yet known what impact Superstorm Sandy will have on the Long Island housing market.