LightHawk requires that you add us to your policy as an "additional insured" primarily so that our legal defense costs are covered if we are sued because you had an accident. Part 135 operators who do any government flying will be familiar with this and may already have multiple additional insured’s on their policy. It is increasingly becoming a standard for all pilots to have to add additional insured’s such as airports and hangar owners.
All legal expenses (your own and those of any additional insured parties) for litigation related to an accident are covered in addition to the liability limits in your policy. There is generally no limit on the amount the insurance company can spend defending itself against the claim, and this expense doesn't reduce your liability coverage. The cost of the claim settlement itself is what is charged against your liability limits.
The only time adding an additional insured to your policy might affect your financial exposure is if the additional insured were deemed to be negligent in an accident. As the PIC, however, you are 100% responsible for the flight, and the circumstances under which LightHawk could be assigned any portion of the negligence associated with an accident in your aircraft are very difficult to imagine. This is one of the reasons LightHawk rigorously avoids placing itself in any position where it could be seen as the "controller" or "operator" of the flights -- instead, LightHawk constantly reinforces your role as the PIC and your responsibility for all aspects of flights, preserving the integrity of your insurance.
There is usually no increase in premiums associated with adding LightHawk as an additional insured, but it varies by broker and underwriter and can also depend on what you think LightHawk flights are all about and how you communicate about LightHawk with your insurance broker. Most LightHawk flights should correspond to what is commonly called a "scenic flight," a fair-weather daytime flight, usually at or above 1,000’ AGL. Terminology such as "air survey" or "resource recon" can have connotations or commercial definitions that imply a much more aggressive type of low-level flying than would be characteristic of LightHawk flights and can influence what your insurance company understands LightHawk's flight profiles to be.