A BROADS day cruiser that capsized causing a 42-year-old woman to drown overturned because too many people sat on one part of it, an interim report into the tragedy has revealed.

A BROADS day cruiser that capsized causing a 42-year-old woman to drown overturned because too many people sat on one part of it, an interim report into the tragedy has revealed.

The Marine Accident Investigation Branch (MAIB), which is investigating why the Breakaway V capsized on the River Bure near Horning Hall on July 19, also says that lessons should be learned from the accident.

Rachel Fry, of Sunbury-on-Thames, Surrey, was in a family party of 10 who had hired the 20ft cruiser when it tipped over trapping her and her sister underneath. Despite the efforts of her sister, from Suffolk, to save her, she drowned.

The interim report says analysis from an experiment involving another Breakaway indicates the boat capsized because of the "loading and distribution" of the 10 people on board.

"The total weight of these persons was about 845kg, and they were distributed primarily forward and starboard of the centreline.

"Six of the party were located on the raised forward deck, which because of its height, had a considerable destabilising influence."

In its report the MAIB makes three safety recommendations.

It says that operators must ensure that people hiring boats are fully briefed and warned of the dangers of uneven weight distribution, particularly on raised decks.

It is also recommends that every new vessel, or any boat which undergoes modification which could influence its stability, be tested before it is put into service.

The Breakaway V – a 6.77m day hire motor cruiser built and operated by Barnes Brinkcraft of Wroxham – was based on a traditional open boat hull form, which had been modified, and to which a "sports cruiser" type superstructure had been added.

The report goes on to state that an "adequate safety margin" should also be set when deciding the maximum number of passengers a boat is authorised to carry, taking into account the potential inexperience and weights of the people hiring a boat, and the worst-case effects of uneven weight distribution.

It reads: "The MAIB considers that this tragic accident highlights the importance of stability calculations and tests on build or following major modifications to vessels, and the need to allow an adequate safety margin when determining the maximum number of persons a boat can carry."

Last night, a spokeswoman for the Department for Transport said the initial findings of the investigation were considered significant enough to release an interim report before the full report is released next year after the investigation is complete.

She said the role of the investigation was to establish the cause of the tragedy, not apportion blame.

The boat's maximum capacity was 10, based on the seating.