The stand-off lasted about eight hours and began at 9.28am when officers responded to reports of a man in distress and possessing a large knife.
A 37-year-old man was later arrested.
He said: "I am writing to give my best support to Sussex Police. Your behaviour has been absolutely disciplined and controlled. May I pay you the highest level of respect.
"A professional police force at world standard. Thank you from The Royal Norfolk Hotel (Leisureplex Ltd) and from me.
"Thank you for taking time out of your day to help us today."