the Duck Tour!
They sit quite low in the water then.
When my brother was in hospital at St Thomas', we'd sit by the river and wonder how they managed to stay afloat when sat that low in the water.
Okay.... let's get this straight... it's a lorry that floats?... I saw wheels....
Yep you drive along the road and then down a slipway and it becomes a boat.
Very James Bond.