But it does not always have to mean a smallish scope and light mount. If you have a balcony, you can bolt a mount into the wall and leave it there permanently and just add the scope when seeing is good. [Timatworksg is working on one].
Because the mount is permanent, chances are that it can take a higher payload and hence, a larger scope. Even in light polluted Singapore, a bigger scope is always better than a smaller scope to show more detail. It is a myth that a smaller scope is more suitable for light polluted areas than a larger scope. The only issue is that a larger scope is indeed more affected by atmospheric turbulence than a smaller scope.
My set up of grab-and-go is more like lower-and-look. I am fortunate to have a car porch terrace which is located below my bedroom balcony. I have just finished setting up my home-made pier mount with a CG5 head [thanks Swimaniac] and a Orion 130mm ST [short tube] Newtonian on my terrace.
As I only paid US$99-00 for the Orion scope during their sale last July and which was brought back FOC through a friend, I am leaving the whole thing permanently outdoors and can risk fungus build up on the mirrors of the scope if my protection method does not work.
Based on my research, I cover scope and mount with a trash bag, then a Mylar sheet,then a canvas sheet. I stick a small bag of silica gel under the scope tube cover to absorb moisture and a box of dehumidifier under all those sheets of cover.
I believe it should work to keep the scope and mount dry.
To access the terrace, I need to lower myself with the aid of a rope from my balcony and start my observation. Hence, lower-and-look.
Actually I will also set up a black screen on the terrace for privacy and to block off the street lights. The screen is attached to aluminium poles which are inserted into tube holders permanently bolted to the terrace wall.
It takes about 5 minutes to start my obs.
Here are a couple of pics-
