Congrats on the new boat. When you say bottle, I think plastic 1 or 2 liter clear soda pop type bottle. Is that what you are talking about? If so, lots of things get stored in bottles like that - to include oil for the steering system....that's where I keep mine - not in a soda bottle exactly, but a clear one meant for such a thing. Do you really mean fuel tank?
As far as "fresh" diesel....yup diesel can and will go bad. However, when stored in an actual bottle with no exposure to the oxidants in the atmosphere and out of the sun, my personal feeling is that is if it is still clear and looking good, then it is probably about is good as you're going to get anywhere. As usual....better to be safe than sorry and any questionable fuel should be disposed of in an appropriate way. Diesel fuel from the gas station is recommended.
BTW....I suspect all SCAN will tell you is to put fresh fuel in it and try starting it up. They'll probably also tell you it will take several cycles to get fuel to the stove unit. If you have a manual, it would be a good idea to read it, because you'll probably have to deal with it locking you out - eventually it just get pissed and goes into a fault mode. I know mine would after prolonged storage. No biggie....just follow the procedure to unlock it.
Again....congrats on getting any awesome new boat!