For clarity, there aren't any export restrictions on ordinary binoculars, like the ones I have, that I suggest as a starting point for boaters who want better means of observation at night. Binoculars are 100 year old tech that you can take anywhere. The only improvements in standard
marine 7x50s in 100 years are that they're now truly waterproof, they last longer, and they have coated lenses.
Night vision devices are different. Copies of the PVS-14 used by the US military are readily available for
purchase in the
USA for a couple thousand bucks each, and are available with various "generations" and qualities of intensifier tubes. The better ones are regulated like munitions. In the
USA they are
legal to own and use but you cannot take them out of the country without an export
license. Doing so is a federal crime. In some countries they're regulated like firearms, and bringing one into the country without prior authorization can result in the same sorts of penalties as bringing in a firearm without prior authorization.
There are thermal vision devices (FLIR) that are perhaps more useful in a
marine environment than night vision. Rather than amplifying available light, they sense infrared and convert it to visible
images. You can buy and posses them lawfully in the USA, prices are in the "couple thousand bucks" range, and the good ones are export restricted just like night vision devices.
In both cases they do
work, and are useful for SAR. You can pick out things like channel markers in the dark, and other boats, but
radar is better for that. So the question then is what are they really good for on a cruising
boat? What do they give you that ordinary 7x50s and
radar do not? And for boats that leave the USA, is the benefit worth the paperwork and the possibility of having to skip some countries where the paperwork can't be approved?