They may not impact the Private Market Flood carriers.  

We had someone quote us a $7500 a year quote on a flood policy and then another insurance carrier offered one under $1000.

He probably obtained it when he was working under a license and is now in violation of the insurance carrier's requirements.

If it's personal, usually you have to have your auto and often times your home policy with a carrier to be eligible for the umbrella (but not always)If it's commercial, it's much easier to only put your rental properties only under the umbrella policy.Finally, if you have any amount of entities (LLC, Trust, etc.) which own the properties, you would want to ensure the umbrella extends coverage over those entities. 

I'll send you the carriers you should check for secondary quotes.Best of luck!

Abbie,Many Insurance carriers will not insure a "Student Rental".  

Cynthia,There are carriers out there that will write a homeowners policy even if it is lapsed. 

Check with your agent to see how your Insurance carrier will handle it.  

If a hurricane comes and wipes it out and carrier finds out its tenant occupied they will not pay.

Don't be surprised if you find best rates for one group with different carriers.