Looking for creative input

[William Brown]

So my parents (I'm 17) have bought a charter boat and started a chartering business which, starting in the fall when i go off to college, they will charter people around and make some absurd amount like 20K a week. So their new business is profitable. Here is where I'm looking for some creative ideas.

The house we currently live in they built in 97 on an empty lot in Northern Virginia, and it recently appraised for around 900k. Right now, we have a tenant in a separated carriage house on the property, who pays rent @ 1100 per month.  Recently we refinanced and got a <3% mortgage, which is good for the next 6-7 years, then it will jump up to 8%. At that time they are planning to sell. But in the mean time, they are planning on renting it while they are overseas and our long trusted handy neighbor will be the property manager. 

Neither of them have ever done anything with real estate, and being an entrepreneurial future investor, I would love to hear some ideas or suggestions to share with them, and to learn from as well.

Thanks everyone!