Is my dock covered by my homeowners policy?
Sometimes, often at a reduced limit, and some carriers exclude structures over water entirely. It is worth confirming by name rather than assuming it falls under other structures like a shed would. Where it is excluded, separate cover is available.
A boat hit my dock. Which policy pays?
Potentially theirs, through their watercraft liability, and potentially yours depending on the circumstances and what your form says about structures over water. It is one of the situations where knowing your cover in advance genuinely changes the outcome.
Someone was hurt on my dock. Am I liable?
You can be, and that is the larger exposure. Liability from people using a dock is a homeowners claim, and the limit matters far more than the cost of repairing the structure.