Marine navigation assisting apparatus

Apparatus for reminding a boatman of the side of a buoy on which said buoy should be passed comprising first and second light emitting devices each having first and second electrodes and each being of a type that emits light of a first color when a first potential is applied to said first electrode thereof and a second potential is applied to said second electrode thereof and of a second color different from said first color when a third potential is applied to said first electrode thereof and a fourth potential is applied to said second electrode thereof, said first and third potentials being different from each other and said second and fourth potentials being different from each other, means mounting said light emitting devices in spaced apart relationship, and switching means connected to said light emitting devices and adapted for connection to a source of said potentials, said switching means being so connected to said light emitting devices as to be adapted to supply in one position of said switching means said first and second potentials to said first and second electrodes respectively of said first light emitting device and said third and fourth potentials to said first and second electrodes respectively of said second light emitting device, whereby said first and second light emitting devices emit said first and second colors respectively, and in another position of said switching means said first and second potentials to said first and second electrodes respectively of said second light emitting device and said third and fourth potentials to said first and second electrodes respectively of said first light emitting device, whereby said first and second light emitting devices emit said second and first colors respectively whereby when proceeding in a channel marked by starboard and port buoys of two different colors a boatman can set the starboard side one and the port side one of light emitting devices to emit colors that indicate to the boatman the colors of the starboard and port buoys respectively and thereby remind the boatman on which side any one of such buoys should be passed.