Navigators have known for thousands of years that the ocean has variable currents, but it is only in the last half century that a reasonably clear picture has emerged of the patterns and causes of ocean currents.
The principal feature of the redesigned checks is a series of printed instructions that the company hopes will help merchants confirm a check's authenticity, which includes reminders to watch the endorsement, compare signatures, and view the watermark while holding the check to the light.