Hi David,
No it's not 1st April and it isn't true either! Having rigged a way of attaching the trailer number plate to the boat to make it more visible (and nearer the back of the boat) than when attached to the trailer, it did make me wonder how long before we do have turn indicators on boats.... There are times when they might be useful; I've resorted to hand signals before now when cutting across the "traffic" going in or out of the mouth of the Hamble! And yes, having taken the photo I did photoshop "SEATERN" onto the number plate in place of my car registration!
Cheers, Peter