The phrase "already in the waters" is correct and usable in written English.
It can be used to indicate that something is currently happening or has already begun, often in a metaphorical sense related to a situation or context.
Example: "The negotiations are already in the waters, and we need to prepare our strategy accordingly."
Alternatives: "already underway" or "already in progress".
In their samples, Buesseler and his "citizen scientists" did detect cesium-137 already in the waters as a result of atmospheric nuclear weapons testing in the 1950s and 60s, and cesium-134 which does not otherwise occur naturally in the ocean and can only be attributed to Fukushima, to serve as a first baseline for subsequent collection, analysis, modeling, and conclusion.
Several of his friends were already in the water.
Arctic ice is already in the water, so melting there won't make much of an impact on sea levels.
Randall arrived in Montauk on a Tuesday night, and by the time I got to the beach on Wednesday morning she was already in the water.
The last thing we wanted to do was to have two of our search and rescue helicopters collide over the one already in the water".
"He was on the pier, she was already in the water, and he could not take the time to go for a boat.
Now they expect it to disappear within a decade or so.Since sea-ice is already in the water, its melting has little effect on sea levels.
A crumbling orange cliff, thin alder roots poking out, Peter's hand already in the water, and the blood thundering into our brains.
By the time I had realised it was Jake, and begun sprinting to the sea, Tony was already in the water and had our spluttering son in his arms.
Since cables that are already in the water can be upgraded at a trifling additional cost, those companies that are dropping them today could soon be pulling out treasure chests.
Today, Lewis is scheduled to arrive in France to oversee the final stages of construction of his Gilles Ollier-designed multihull, a direct sister ship to two vessels that are already in the water, the New Zealander Grant Dalton's Club Med and the Frenchman Loick Peyron's Code One.
