Are the effects of Jetski Palooza's business a postive or negative externality?

If there is no mitigation or law stopping Jetski Palooza from running their business, will the price Jetski Palooza charges be too high or too low for society's optimalization?

If there is no mitigation or law stopping Jetski Palooza from running their business, will the price Jetski Palooza charges be too high or too low for society's optimalization?

What if the fishermen and paddleboarders realized that Jetski Palooza was earning $$40,000$ a year, but they were losing $$100,000$ plus the ability to paddleboard. With no government involvement, what might make economic sense for the fishermen and paddleboarders to offer Jetski Palooza? Why does that make economic sense $($please explain using numbers$)$

What are some ways that the government could step in to mitigate the externality of toxic orders. Come up with at least two ways.