Having previously relied on my faithful G-Shock for the past 5 years it was time to upgrade. It was a straight choice between the SPF-40 or the similar Pro-Trek. Went for the Sea-Pathfinder and couldnt be happier. Big face, reassuringly heavy, and with loads of functions including barometer, countdown and split timer stopwatch, tide graph, lunar phase graph, digital compass-the works. Spend 15 minutes aquainting yourself with instruction manual and its fairly simple to operate. A recommended buy.