In Florida they can only sue if they can prove neglect. But theres always a chance they can. If your not apposed to letting folks use some of the lake then maybe start how ever many feet in from the begining of the lake so you have a large private area from one side of your property to the other. Or run a fence 100ft off the shore if you donr mine total acess. If you do mind period, then fence is your only option. Less you want to tie rattle snacks up to trees like a moon shiner. But again, lawyers wuld have a field day. Maybe you could use a good fence where it's a real issue then string bobwire on the rest to save money.
One great way that might work long term are thorned shrubs. The germans used a citrus variaty that hardy has leaves, cold hardy, and no fruit. It made it un passable. Down here bougainvilla works real well with 2in razer sharp needles. Bougy's grow about 10x10 no problem so planting them 5ft on center would cost about a dollar a foot if you buy from a wholeseller. They grow fast enough to fill in in a year and forcing a path even from young, aint happening with out armor. Though you will likely need to look into a diffrent plant. Maybe a hearty shrub rose.