A 60-foot houseboat has sunk taking with it the treasures of the two elderly residents.
The vessel sank into the River Hamble shortly after midday and diesel has been leaking from the wreckage.
The boat was moored at Cabin Boat Yard, Bursledon, and it was fear that a tank with 70 galleons of fuel had been breached but it is currently secured.
Parts of the river are being booned to minimise the damage.
River Hamble Management Committee chairman Sean Woodward said: "We are working to protect the diverse ecology from further damage and the Environment Agency will be involved."
The Red Cross is taking care of the two men who lived aboard and arranging alternative accommodation for them.