Sunday Swim: Sea Monster Off the Port Bow!

 Once in a blue moon, the North Sea off the North Norfolk coast becomes so warm and crystal clear, that it attracts a certain cryptid lifeform to its inviting waters.
 Unfortunately, I didn't realise that today was one of those "blue moon days", and popped down to the beach here in Overstrand for a late-afternoon dip.
 Things were going swimmingly until a sudden chill alerted me that something wasn't quite right...

Half past five and all's well

Groynes extend into the startlingly clear sea

At the risk of being branded a floozy, I chose a different groyne (from yesterday's) to sit astride while I prepared to get wet

After getting out of my depth (but still able to see the bottom!), I returned to shore

Despite having dried off, dressed, and being sat in the sun, a sudden chill passed through me.
Something was wrong!
And, near the horizon, the Vos Gorgeous appeared to be powering very quickly away.  But from what...?

Yikes!  Sea monster off the port bow!
Oh, hang on... It's just my sister, Indescribable...  Run away!  Run away!