It amazes me that although DSC has been around for over 10 years, so few people use it for for private purposes - hopefully you never have to in an
emergency.
Folks will spend hours trying to contact sailing buddies then have a lengthy voice exchange clogging up a channel for several minutes, just to establish each others position.
Although DSC on HF IMO is of very limited value for private use given the range of frequencies, modulation, propagation etc, on VHF where you have a limited range of channels, & know the range & capabilities it makes so much more sense.
Once you know your buddie(s) MMSI number you can program it in to your DSC VHF & have the following digitally controlled facilities to another DSC/VHF transceiver:
1) Call his/her radio with request to change to a channel of your choice in order that you can conduct a voice exchange. If the radio being called has auto ack enabled it will switch to this requested channel.
2)
Poll his/her radio for their position - reply can be automated so within a couple of seconds you see their position displayed on your radio.
3) Send your position to him/her.
4) Answer any of above requests sent to you manually, or have your radio answer automatically if you have auto ack enabled. This is very useful at night time if you don't want the sleeping crew woken with the loud DSC squawk you get otherwise.
These are just the private functions, you can make Emergency, All Ships & Group calls as well.
If you have a VHF/DSC transceiver you have all these facilities available to you now. To set up is simple.
Connect your GPS to radio
Enable DSC watch
Enable auto ack (aknowledge) if you want to automate the replies to DSC calls as mentioned above.
How to do this obviously varies between models but it will be shown within the pages of the manual which you glossed over when first installing the radio
DSC range I have found to be slightly less than acceptable voice - say 28nm for DSC & 32nm for voice as a rough average over clear
water for well set up radio's. This can vary enormously depending on terrain between boats though.
Hook it up, set it up then try it out - you will be amazed how easy it is.