The reason banks require comprehensive
and collision coverage
on a vehicle in storage is because it could be damaged by a fire or a collapse of the building in which it is stored. In addition to the bank, Massachusetts
requires any vehicle registered in the state to also be insured
. If you took the vehicle off of your father's policy you would have to return your license plates/tags to the state until you re-insure it. It's possible that getting yourself removed from the policy and paying your father for the vehicle's portion of the insurance premium while you're deployed would be the least expensive option. However, there are two other options I would recommend looking into.
First, I would contact USAA and get a quote for your vehicle. They offer accommodations for deployed service members who are insuring a financed vehicle with them. The second option would be to contact a local insurance agent in your area and inquire about a physical damage only car insurance policy. This type of policy only covers the vehicle against damage, which is what your bank requires, but does not provide any state required coverage. If you go this route then you will be required to return your plates and registration tags to the state.
Unfortunately you won't be able to completely avoid insurance costs, and there is no way to tell which of the three options will be the lowest until you get quotes. Call USAA for a quote, call a local agent about physical damage only insurance, and have your dad contact his insurance company to find out what your vehicle would cost to insure if you were removed from the policy. This will help you determine which option makes the most sense for your situation.