Emergency services and Loch Lomond rescue boat volunteers were called to the scene near Boturich shore and Balloch Park at about 17:00 on Thursday.
The volunteer team assessed the man’s injuries and transferred him by stretcher onto a lifeboat. Meanwhile, the jet ski was secured by a park ranger patrol boat.
Paramedics took the man into their care, and he was taken to hospital. Rescuers left the scene at about 18:10.
It follows a warning to jet ski riders from the Loch Lomond & The Trossachs National Park Authority on Thursday.
The park authority said it would increase patrols this weekend in an attempt to stamp out a rise in what it called “dangerous, reckless and aggressive behaviour”.
The Loch Lomond byelaws, which were strengthened in 2023, are intended to ensure safe and responsible use of the loch via speed-restricted areas and other measures.
Once again, my thought are to ban them, there is a place for Jet Ski’s and it is NOT Loch Lomond, the Park Authority are weak on this but great on dubious planning permissions, as usual, the Authority despise the Free Press. Just the same as WDC do, in this allegedly free Country, which we are not, our Bank Accounts are snooped on, another subject for another day, what the h… did I as as Veteran support the UK for, Brigadier Pearson will be turning in his grave, if he had a whiff of the state of the UK now, being fierce has achieved nothing, WDC Leaders you are a disgrace and money salaried and Pension grabbers, I don’t care what I say any more if it is PC or not, going to die without my carer anyway