AIS Vesper Watchmate Transponder WMX850

When I built Malua I set-out to select the very best equipment on the world market.  That was around 2000 to 2004.  I took hours looking at catalogues, reading reviews in hard copy magazines and talking to many, many people.  I had been sailing all my life so I knew roughly what I wanted.  I definitely knew the brands I would not touch with a barge pole both hardware and electronics.  Malua was finally launched with the best equipment to suit my sailing requirements.  I have added extras over time as the requirement is needed.
At one time I would not put a wind generator on Malua but with the technological advances in blade design the noise that the new ones make is quite acceptable so it is now time to install a modern designed wind generator – more on that later.

One item that was missing on the original list is an AIS (Automatic Identification System) Transponder.  It has taken a number of years for the technology to mature and the airwaves to be cleared of non-AIS traffic but today there are a number of units that reach my look-at list.

The requirements are simple: a stand alone unit – not connected to a computer (if the computer does not work your AIS wont help you and having seen too many blue screens of death I wont depend on a windows PC). 
The second is a transponder.  It is all very well to see another vessel but why not put the obligation on them to take action to avoid you.  If you don't transmit your position then it is all up to you.  Remember COLREGS Rule 5 …..proper look-out by sight and hearing as well as by all available means.  The last phrase is the key one.  Therefore the AIS must broadcast your position and course.
The third criteria was low power usage because it will be on all the time while making a ocean crossing and one doesn't want to drain the battery just for the unit to wait for a passing ship.
The fourth was the features which had to include all the normal CPA (Closest Point of Approach) etc. but more importantly if the vessel will pass ahead or astern of you if you maintain your course.  This element is missing in many brands of AIS – why I don't know.

Having studied the market and followed the blogs and discussion groups it came down to two units: the Simrad A150 because all the other electronic equipment on Malua is Simrad.  However I rejected this unit because it was 1st generation and their service record for old equipment is very poor.

General Display

The second unit from Vesper Marine has been developing over the years with very good reviews.  I chose the Watchmate WMX850 as the best in line prior to the launch of a touch screen model.  I then set about sourcing the unit.  These days of the Internet it is only a click away no matter who sells the unit.  To my surprise I discovered the manufacturer Vesper Marine is a New Zealand company.  The local Australian distributor, a company I have had an issue with in the past, has as its manager an old acquaintance who has moved around a bit but now sells these units.  One phone call and two days latter the new Watchmate was in my hands.  A great price, good service and I know a great support mind if I ever need it.

Vessel Info

As with all previous equipment I set it up on a makeshift panel and switched it on in the front room of my coast house.  Bingo two tankers passing up the coast 38nm miles away.  Well that is very good because that is well over the horizon and I would have thought out of VHF range.  I was able to track them as the passed abeam of my signal on the cliff top.  I wonder what they though of this yacht about 200m inland!

The display is simple to read and indicates if a vessel will come within your target range.  It has an option of excluding a vessel which may be accompanying you on the same path and you don't want it to set off an alarm all the time.  This is an issue in a rally and especially annoying with most radars.

CPA Screen

The unit lets you easily change the range from harbour, coastal and ocean and also exclude vessels at anchor.  It has all the normal features regarding the target vessel's details, course, speed and direction so that is not exceptional.
It captures weather reports and can send a AIS Mayday message from the transponder which will supplement the DSC distress message.  Hope I never have to use this or even receive one.
I also like the USB and RS323 port outputs so you can integrate the system into my current chart plotter or computer tracking systems.  I have added a loud alarm which should wake the dead.
I purchased a stand alone GPS receiver unit and an additional ¼ wave length antenna so it will not directly interfere with the other VHF antennas transmissions.  Both units will be mounted next to the solar panels on the aft structure.
Now all that is required is Malua and some water.
UPDATE
I installed the device and attached the GPS to the stern stainless steel structure - it also hold the two solar panels.  The metal of the GPS is grounded to the stainless steel.
After using the Watchmate three times it would not switch on.  Removing it from the bulkhead I could see that a component in the Watchmate had burnt out. 
I contacted the Oz agent who put me in touch with the designer who after a few questions analysed the problem.  It seems that the GPS should be totally stand alone with no contact with the ships negative.  The exchange of emails with Vespermarine was the most impressive service I have ever received from any supplier.  Immediate, direct and with the knowledge of their product and how it works on a vessel.  They have dispatched a new unit for me and will wait to take mine apart  when it finds it's way out of the French postal system - now there is a story.