TIMEX Marlin Water Resistant Series
Marlin is the hand winding water resistant series of TIMEX regular sized mechanical men's watches. In the early 60's the M22 movements were used. In the late 60's through late 70's the M24, M25 (date), M27 (day-date) and M105 (date) were used.
You can recognize a TIMEX Marlin by the printed waterproof or water resistant on the dial. Notice that other TIMEX models also can have water resistant on the dial. Case size and other things printed on the dial determine what TIMEX series it concerns.
TIMEX Marlin waterproof ref. 26061 from 1972
Timex US Catalog 1977
Waterproof vs water resistant and 25 Metres
When did waterproof change into water resistant and what is there to know about the watches with 25 metres on the dial? You can read all about it here.