Passage through waterways has been a party of Zelda for years, but Okami saw fit to get started on this untapped method of transportation right away. After just a few hours, you've already got a massive amount of land to cover, so tossing a mermaid coin into select pools for quick, easy access to teleporting waterways is a life saver... in 1992's A Link to the Past. Yeah, it wasn't a coin, it was a pair of flippers, but now we're just splitting hairs.
In Wind Waker, you use the same baton to whip up tornadoes, not water, but the interface does look awfully familiar sitting next to Okami 's map of the same feature.
Above: Other Zeldas actually used waterways, but this image speaks for itself.
Another Link to the Past hallmark that made its way into practically every Zelda since is the Hookshot, a spike-on-a-chain weapon that pulls you across large gaps. In Okami, you use the Celestial Brush to draw connecting lines between you and your destination, but the effect is the same. Also, in both games you can only use this weapon/ability on specified objects - in Zelda they're little targets, while Okami uses hovering flowers.