Mr Ramsay thinks he was travelling at 40km/h when his boat crashed head-on into his friend's.
The impact shunted him into the front of his boat, partly trapping him and collapsing his steering wheel, knocking him unconscious and leaving him with four broken ribs, a dislocated knee and dental damage. His passenger suffered a knock to the head and was also taken to Waikato Hospital.
His friend's passenger had what was believed to be a dislocated knee.
Mr Ramsay said he was surprised the matter was heading to court after he said investigations by police, the harbourmaster and Maritime New Zealand found nothing wrong.
But asked if would defend the charge, he said: "Nope".
"Who would be an idiot to try and take on the Waikato Regional Council? They're too big. I just see it as a waste of resources, a waste of money and a waste of time.
"The guy (from the WRC) was down here a day after the accident measuring up my boat - when that happens you know you're doomed."
Mr Ramsay, who returned to work on Tuesday after a five-month lay-off, admitted to breaking a number of rules including travelling above 5 knots at the time of the accident.
"One of the maritime rules of the waterway is that you always pass on the right-hand side but I got caught nailed to a bank on the left. It was like I was driving on the wrong side of the road.
"Do you think you'd get prosecuted if you were driving on the wrong side of the road and had a head-on [collision]? I'm pretty sunk aren't I ?"
Mr Ramsay said he would likely be fined.
He is going to sell his 3.7m boat to meet the costs and downgrade to a smaller vessel, though he has no plans to give up jet boating.
WRC navigation safety programme manager Nicole Botherway said the incident, which could potentially have led to fatalities, was a reminder about the need to take extreme care while operating powerful jet boats.
"It's always important for people using jet boats and other craft to watch their speed around other water users.
"The rule is that craft should stick to five knots or less within 50m of other vessels or swimmers."
Mrs Botherway said the council used education, warnings and fines to reinforce water safety rules.
"And, where the situation is serious enough, the council is also prepared to take people to court over safety issues."
She urged all boaties to take extra care over the Waitangi Day holiday weekend when it is expected that even more people will be out on waterways than usual.