Blackwater Sound: depth, boat ramps and water quality
Boat: 3 ramps and launches on file for this water.
Start here: Launch at Caribbean Club Pay Ramp, 2 lanes, concrete.
The estuary
Blackwater Sound covers 7,646 acres in Florida, across Monroe County. It is an estuary: the deepest point measured is 17 feet (5.2 m). Our records hold 8 species for this water.
Depth: down to 17 ft at the deepest measured point
Deepest measured point: 17 ft (5.2 m). We hold 37 depth contours for this water, drawn from 29,650 soundings.
Water and conditions
Water clarity runs 6.6–9.8 feet on our readings, averaging 8 feet, from 62 readings. Water temperature averages 80°F across the year. The coldest single reading we hold is 62°F and the warmest is 93°F; the warmest monthly average is 90°F. pH averages 8. These readings span 2016–2025.
Monthly average water temperature: Jan 68°F · Feb 72°F · Mar 79°F · Apr 79°F · May 84°F · Jun 86°F · Jul 90°F · Aug 87°F · Sep 86°F · Oct 80°F · Nov 75°F · Dec 74°F
3 ramps and launches on this water
On this water we hold 2 trailer ramps and 1 boat ramp.
- Caribbean Club Pay Ramp — 2 lanes, concrete, parking for 18 trailers (paved), paid, portable restrooms, dock, lit for night fishing. Key Largo. 104740 Overseas Highway, Key Largo 33037
- PonTunes Key Largo Boat Rentals, Marina and Tiki Bar (Small Boats - Parking Off-Site) — 1 lane, concrete, parking for 10 trailers (firm unpaved), paid, needs repair. Key Largo. 107690 Overseas Highway, Key Largo 33037
- Marina Club Key Largo at Blackwater Sound — Key Largo. 103950 Overseas Highway, Key Largo 33037 · phone +1-305-453-0081 · website marinaclubkeylargo.com
Fee and opening hours are blank for all 3 places in this list: a blank means we hold no such field, not that it is free or always open, and this list may not be complete.
What is hard here
Wind is the limit, not the fish: 7,646 acres of open water build a short steep chop, and there is no shelter in the middle. Summer water sits at 90°F: heat and afternoon lightning are the real risks, not the fishing.
Where this data comes from
- NOAA Digital Coast — NOAA Digital Coast bathymetric lidar: class A, a survey of the bottom, 2018.
- USACE eHydro — USACE eHydro channel surveys: class A, a survey of the bottom.
- NOAA BlueTopo: class A, a survey of the bottom.
- NOAA National Bathymetric Source (S-102 ed3.0.0) — NOAA S-102 bathymetric surfaces: contours: class A, a survey of the bottom.
- NOAA ENC — NOAA Electronic Navigational Charts: soundings: class A, a survey of the bottom.
- NOAA ENC — NOAA Electronic Navigational Charts: depth contours: class A, a survey of the bottom.
