Police were called to Volt Avenue, North Acton shortly after 11pm on Saturday, 30 January to reports of a large gathering on a moored boat.
Police attended and located the party which was attended by more than 70 people.
The group was dispersed and a total of 72 people were reported for the consideration of fixed penalty notices of £800 for attending an indoor gathering of more than 15 people in breach of the Coronavirus regulations.
The organiser was identified and reported for consideration of a £10,000 fixed penalty notice.
Detective Chief Inspector Thomas Bowen, of West Area, said: “This was a blatant breach of the Coronavirus rules that are in place to save lives and protect the huge pressure on the NHS.
“All the people who attended this event, which appears to have been organised on social media, have quite rightly been reported for the consideration of fines.
“The Met will continue to shut down and disperse events such as this, which risk spreading a virus that has already claimed the lives of more than 100,000 people in this country.”