Two things...
First...remember weather does play a factor...your defenatly easier to spot in the day or night with clear sky, then with rain, and or fog. It's also not always about being spotted on the surface. If its a calm day your parascope will leave a wake, as on windy days, its quickly broken up by the waves.
Secondly, I've learned You will generally spot them before they spot you, so for me at least as soon as I make visual contact, I send my report and dive well below the thermal layer in case i was spotted, I can't be further tracked, well not as easily tracked.
Good hunting
