The Royal Navy has a bunch of coastal patrol vessels that are named after rivers around the UK.  From what I have read, HMS Severn is one of the first batch of vessels and it is less capable than the later batch.  Although originally planned for retirement, it has been kept in service patrolling the UK coastal region.  It was heading out of Portsmouth when I saw it.  I think it was originally painted grey when it was commissioned but it currently has more of a camo scheme applied.  It made me think of the disruptive camouflage used during the First World War.  I actually shot a pano of it as it headed out taking advantage of the lack of an immediate background to avoid any issues with the movement between shots.