At least 26 people died when their boat sank on Lake Albert, which marks the border between Uganda and the Democratic Republic of Congo, Ugandan officials told AFP on Friday.
The boat was carrying passengers between two Ugandan locations in the lake's northeast on Wednesday when it "hit a strong wind" and "went under water", local official Ashraf Oromo said.
"The boat had over 50 people on board, 26 bodies have been recovered, 21 people were rescued," Oromo said.
"A search is ongoing and no more survivors are expected."
A regional police marine officer, Samuel Onyango, confirmed the accident.
"Because of failure to adhere to safety measures and fast changing weather patterns, Lake Albert has many accidents," Onyango said.
Eighteen people drowned when two boats capsized in separate incidents in northeastern Democratic Republic of Congo in June.