It partly depends on your gear and what you use it for. If it's normal consumer grade (cheap) stuff, you could add it to a homeowner's policy. If it's professional grade (big $$$) or you use it for professional work, it won't be covered by any homeowner's policy, so you need what is known as an "Inland Marine Rider" policy. I used to insure my camera gear with a Marine Rider policy because it covers any and all damage (even if I drop it), theft, etc.
Google around on that phrase "marine rider" plus "insurance" and "camera" and you'll get a lot of hits. Here's an example from the well-regarded Luminous Landscape website.