Buoy hopper is designed to be used at night, it is for hopping between buoys and making port entry and exit passage plans into harbors, or in the open water.
No more fiddling with a torch and a piece of paper.
It will simulate the light characteristics of Buoys and light houses at night. These are complied into lists with instructions and bearings.
It is best used in multitasking mode on iphone OS4 in conjunction with a chart plotter, but is still very useful on old models.
iBuoy hopper also has a large edit screen that can be held up next to the buoy in question for easy comparison.