Dursleys getting back to the land

[karen.sellwood at pearsoned-ema.com]

No: HPFGUIDX 28450

Hello, I'm new to this site.  I know that this question has come up 
in the past (it's in the FAQ - Mysteries section that I came across 
whilst surfing), however, I was wondering if it had ever been solved. 
I have searched for posts relating to this question, but to no 
avail...

How did the Dursley's get back to land after Hagrid and Harry took 
the boat in Philosopher's Stone?  Did they swim?  Shout for help???  
Any suggestions welcomed.  And apologies for going over old ground : )