Re: Flashlight with long useable throw.
Several come to mind, but what do you mean by really good throw. How far and for how long at a time? I boat on a river and get by with a Manker U22, which can light up the next buoy down river (1000 meters) for about a minute before it starts ramping down for heat. Also, buoys are painted to easily reflect a beam and thus fairly easy to see. If the desire is to light up significantly further or illuminate things that are more difficult to make out at a kilometer or more, then you might be better served with purpose made boat search light. That said, there are some handhelds such as Acebeam's K75, which can reach out a couple of kilometers and really do a good job illuminating things at one kilometer. However, it will get hot pretty quickly, as will most handheld lights. The main advantage of the purpose built mounted boat lights is that normally they are designed for extended operation without heat buildup. Of course, they do eat power, so they also have a downside.