So it seems that at this stage it would cost me about the same :
To can the Lowrance HDS-5M (sell it on Ebay) and buy a Garmin
To keep the Lowrance and buy a Garmin
The problem with the HDS is that things that are important to a cruising sailor are not mentioned at all and/or are an afterthought.
Try this. Download the Garmin 546 manual and look in the index for a) AIS
and C) Calibrate paddle speed. There are useful sections explaining the AIS
Now try the same with the Lowrance. There is no mention at all in the index of the above. No mention of the DSC capabilities. Virtually no info about the AIS ones.
This device has fallen well short of my expectations so far.