Two Israeli men, a father aged 66 and his son, 43, suffered bruises in the attack. Unusually, the dust-up happened at a beach where jet-skis are not allowed.
But this is Phuket. Kata Noi is perhaps the most tranquil beach on the island's west coast, backed almost its entire length by the five-star Kata Thani Resort.
When the jet-ski operator took to the tourists with the No Swimming stick about 1pm today, a large crowd quickly gathered and the culprit was unable to make his escape.
Case officer Lieutenant Channarong Prakonkua told Phuketwan tonight that at the time the younger Israeli man hired the jet-ski from Kata beach, the next beach to the north, there did not appear to be any problems.
However, after the man paid his 1600 baht for half an hour, the jet-ski ''felt wierd'' so the tourist beached it at neighboring Kata Noi.
He then went back to Kata and accompanied the jet-ski operator, Danaichet Yomjinda, 25, back to Kata Noi.
It was here that the usual jet-ski ''who is going to pay for this'' debate flourished, and the argument went on for some time until the younger israeli gave the keys back to the jet-ski operator.
On any other beach, there would be other jet-ski operators who would quickly gather but Kata Noi does not see many jet-skis.
So, according to the lieutenant, emotions boiled over and the jet-ski operator allegedly took to the Israeli, and to his father when the older man tried to intervene, wielding the No Swimming stick.
Khun Danaichet was bailed late today on two charges of assault. It is believed the No Swimming sign is being held as evidence.
No update has been provided on the condition of the jet-ski.