The grounds · 180 ft · banks, ledges and wrecks

Sailfish

Istiophorus platypterus. Prime water reaches Cape Hatteras in Southeast Atlantic right now (78°F at the surface). Fish it 16–179 ft down — that is where 83–80°F water sits off Cape Hatteras.

LaneThe grounds · 30 fa (180 ft)

Depth it holds98–656 ft

Prime water75–86°F (workable 75–90°F)

Holds in the column16–197 ft down below the surface, over 98–656 ft of water

Judged onsurface temperature (NASA MUR satellite)

Structurenone

The water column off Cape Hatteras

The strip is the water itself, coloured by temperature from the surface down to the 179 ft surveyed bottom at that spot — one band per RTOFS model level. The outlined stretch is where Sailfish's temperature band (75–90°F) and the depth it holds actually overlap. That thickness is the number that matters: it is how much water you can work, not just whether the spot is warm enough somewhere. One model cycle, not a weekly archive — this holds still while the surface map scrubs.

In 3D

Drag to rotate, pinch or scroll to zoom. 3D model traced from a Duane Raver, Jr., Public domain (same illustration Commons attribution) reference — source.

How it's fished

Kite-fish live baits on color changes and showering ballyhoo.

Region by region — right now

Region	Season	Prime water	Temp	Fish it at	Months
Florida Keys	off-season	reaches Islamorada	86°F	16–176 ft	J F M A M J J
Southeast Atlantic	in season	reaches Cape Hatteras	78°F	16–179 ft	J F M A M J
Gulf of Mexico	off-season	reaches Tampa	86°F	16–181 ft	J F M A

"Fish it at" is where this species' temperature band and its holding depth overlap in the water column, from the RTOFS profile (13 levels, 0–300 m) — the depth to actually put a bait, not just the place. "Prime water" is the furthest sampled station on the 30-fathom lane whose surface temperature sits inside this species' band. It is water, not a sighting report.

Charted grounds on the 30-fathom lane

Flower Garden Banks