The victims were identified as Valsakumar, a 50-year-old Indian, and Herathu, a 50-year-old Sri Lankan.
Valsakumar is survived by his wife and two children.
They were part of a 15-member group on a holiday trip to Taqa beach in Salalah. Of the six people who fell into water, two drowned and four were rescued.
"The retreating waves were very powerful. This might be the reason for the accident," one of the victims' friend was quoted as saying by Times of Oman.
The victims had worked at the Ministry of Defence base in Thumrait for the last six years.