It is a bit of a game isn’t it.
I have changed the batteries in my one 4 or 5 times in the 10 years plus that I have had it.
The shaped O ring has given up the ghost in mine.
Tried to find a replacement on the net without any luck.
One company would fit a new one for me as part of a service for £80.00.
I will just have to keep it out of the water.
The Lunitidal info is not too hard to find in the internet now but was a struggle 10 years ago If one had miss placed the instructions.
It is a great watch in my opinion.
I wear it most of the time and would miss it if I lost it.
I do leave it down below when sailing these days due to its lack of waterproofing and the fact that it can fall of at times due to a not perfect replacement of the pieces that join the watch body to the titanium strap.
Mines about 5 years old and going strong-bits are available online-bought mine from
"Watch batteries"-just Google them-they also have spare bits-straps etc.
My wife generously bought me a 80's Omega Seamaster for my 50th. She also bought me a Casio Sea Pathfinder so I didn't wear the Omega on the boat! Only the cheap casio, though. No tide graph on mine.
Has this name been used for more than one model over the years? I bought one a year ago. (£20 from Argus IIRC). It has the moon phase and tide hight displays, but also has printed at the bottom of the dial "10YEAR BATTERY" which I would take to mean that I should expect a battery life of 10 years. My previous Casio watches (more basic models) have easily managed that: the strap has in each case gone before the battery. In fact the old (strapless) one in the chart table drawer must be approaching 20 years old and as of 30 seconds ago was still working...
The original batteries on my all singing, all dancing two sensor blah-blah Sea-Pathfinder lasted two months. The glass has been etched by a light domestic chemical cleaner, the hands are impossible to read in some lights it costs £80 to replace the batteries and keep it waterproof - if you can find someone to do it. It's rubbish! I'll be buying a cheapo from now on.