Ronnie,
Fee advice is often not worth the cost.
But -
I will throw my 2c in anyway.
What you are planning is complex enough to lack reliablity. This is not
something that should go with the red button.
Yes, it sounds like a good use of existing equipment (assuming the plan
below does not include acquiring anything), but actually getting it to
all work once and then stay working on the water is a different issue
altogether.

I am a great proponent of DSC radios with MMSI set and active GPS link.

My advice - campaign E-bay for a Cheap Old Garmin, Magellan or Lowrance
that has a data/power cable included or is easily acquired. Put it on
the boat, hook it up and make sure it is turned on like the radio when
you are getting underway.

Keep the PDA for doing other things.

This is what I do.

Matt Colie - Yachtsman's Technical Support www.yachtek.com

Ronnie wrote:
Our small motor boat is fitted with a DSC VHF radio which accommodates
a GPS positioning input using NMEA. I'd like to employ a removable
GPS unit, mounted in a cradle next to the radio. So far, so easy. For
my work, and during leisure time, I want to use a PDA running Email
with Word/Excel etc, and a PDA combined with GPS would enable me to
carry only one device around with me out of the boat. Two PDA
manufacturers make a device - HP 6910/6915, and Fujitsu Siemens Loox.

PDAs are 'USB' oriented - and the manufacturers do not appear to have
NMEA compatible cables for connection to a DSC radio.

Has anyone used a PDA with GPS as an NMEA source for a DSC radio?
What kind of cabling and connections were employed to the radio?

(Googling didn't reveal a FAQ/howto of any sort on this, nor any
similar Usenet query, though I am sure this question must have been
asked before. Apologies if it has been and I couldn't find it.)

______________
best wishes,
Ron