The Seiko 6159 7010 dive watch, also known as the " Grandfather Tuna" was first sold in 1975 and the depth rating of 600 did not have an "m" after the number. In 1976 and until the end of its production, the depth rating read 600m. This makes the 1975 model more desirable for Seiko collectors.

This particular watch that I acquired recently is a 1975 model and the condition is very good considering that most of these watches were used for water sport activities. The titanium shroud and case has no visible wear and the bakelite bezel has no visible cracks. The dial also is pristine with beautiful patina on the hour markers that matches the hands.

Its getting harder to find a good honest example of this watch so when the opportunity came, I grabbed it immediately to add to my 2 other tunas.

 

Really nice looking bezel, this makes me miss mine!

 

I really like wearing this tool watch. Its big but light because of the titanium case and very well built. With its high beat (36k bph) movement, I love watching the second hand as it glides so smoothly across the dial.

 

Absolutely, and totally purpose built. Here's a photo of mine before I let it go.

 

Very nice. Is that an ISOfrane strap?

 

Couldn't help but jump in and show off my Golden Tuna . In great nick for a nearly 40 years old watch

 

Thanks! It's actually a straposphere strapiso. Really great for the price imo.

 

Well done!