Archie,
So very pleased that the damage to you and your daughter is not life changing, just terrifying.
I guessed that something had caused a loss of steering control, but never thought that hitting standing water could cause such a profound loss, resulting in a roll over.
That the Roll bars did their job is good to hear, I had a bar fitted to the Plus 8 because after having had the screen side struts changed and realised that the screen on a Trad Morgan offers no more support than the screens on a M3W I felt it essential.
OK, perhaps the Aero Chassis Plus 8 is more stable than the M3W, but I really don't want to put it to the test.
Good luck finding a replacement with 3, or 4, wheels!