Here is a shot of the scene, taken from a vantage point on Westminster Bridge.
You can see three four vessels, but the large boat to the left doesn’t appear to be relevant to the incident.
A police boat is to the right, with the orange RNLI boat in the middle.
The second-from-left boat appears to be the point of interest, where the emergency services are focused.
However it is not clear what the nature of the boat is, and why attention is centre on it.
