When I read this I thought it was going to be a completely different warning.
So, I'll add mine to the thread.
Like your's my RIB didn't have a drain plug at the bottom of the transom when I got it, relying instead on a well with a bilge pump.
I also decided to fit one, and dutifully drilled a large hole as low as possible and fitted a threaded tube with a screw in bung. Great thought I.
Now comes the moral of the story.
When you launch your RIB with it's handy plug to let water drain out whilst on it's trailer -
Remember to fit the bloody thing before it goes in the water.
On too many occasions I've parked the car and trailer only to find the screw in bung still on the boat key keyring.
It's hard to reach down that low on mine to fit it, and when you've launched into a busy fishing key like the Camber the water isn't the nicest to reach down into.
Nos4r2 will remember the day he had to hang onto my legs whilst I dangled over the back desperately trying not to drop the bung whilst I started the thread underwater.