Radars are a necessity when boating at night or in fog. There has been great advances in the last few years in this area in the form of FM modulated radars. Instead of just relying a pulse return, the frequency is swept and returning pattern relative to that is used for detection of targets. The result is a radar that can run at much lower power allowing use of solid state technology instead of tubes. This means little warming time and much safer radar due to reduced radiations. This is a good video on the Simrad 4G unit that I recently bought to replace my older technology unit. BTW, this technology was invented during World War II but it has taken this long to make it cheap enough for consumer use. Here is a nice overview of it. Sadly it is a very low resolution video but still usable: