This is the dramatic moment a bedridden grandmother was rescued by jet ski athletes during severe floods in southern Thailand.

The pensioner had reportedly been trapped in the deluge for two days after the torrent submerged home in Songkhla province, where more than 100 residents have died.

Emergency crew raced to the family's single-storey residence on November 29, where the raging floods had blocked all doors and windows.

Harrowing footage shows the ill grandmother lying on a waterlogged mattress, her head barely above the murky water. She could barely open her eyes, and her hands had gone pale and wrinkled from prolonged immersion.

Volunteers battled to lift her through the rafter gaps, dragging her onto a waiting boat as she remained limp throughout the rescue.

The pensioner was rushed to a hospital for treatment.

Jet ski athlete Oraphan Teerapatpanich said: 'I don't know how she survived for two days. This is her second life.'

Members of the Jet Ski Association of Thailand were volunteering to help in evacuation efforts during the flood crisis.

Two days earlier, jet ski champion Supahlak Ninnopparat, 34, rescued a mother and her newborn baby from a swamped home in the same province.

The death toll reached 176 as the catastrophic floods, described by Prime Minister Anutin Charnvirakul as 'the worst flooding in 15 years', swept through southern Thailand.

The premier on Saturday apologised for the government's bungled flood response amid public outrage, telling them 'that the government was unable to take care and protect them'.

Songkhla province suffered the highest death toll, with 131 fatalities. Hat Yai district was among the worst-hit areas, recording a staggering 13 inches (335 mm) of rainfall in a single day on November 21.

The Southern Eastern Meteorological Centre said a strong monsoon trough had caused the heavy rainfall.

Thailand and neighbouring countries in Southeast Asia are in their annual monsoon rainy season which sees soaring temperatures followed by powerful rain storms in the afternoon leading to widespread flash floods.