Bellport Bay (see Chart ) is a protected lagoon separated from the Atlantic Ocean by a barrier island (Fire Island).

In the racing area, the following conditions prevail

Water Depth:   4 - 7 feet
Water Temperature in July:  ~75 ^oF
Tidal Range:   10 Inches
Tidal Currents:  Minimal, Flood to the West, Ebb to the East
Power boat traffic: Minimal except in the main east-west channel
Seas: 0 to 2 feet

Winds (Local):  Light offshore in the early morning with a SW sea breeze developing mid-morning, increasing to 11 to 15 kts by late afternoon, diminishing toward sunset.  Under sea breeze conditions, winds under the lee of South Howells Point have a tendency to diminish and back to the south.

Winds (Synoptic): The effect of the "Bermuda High" during the summer  may augment the strength of the sea breeze.  After a cold frontal passage, strong winds from the northwest can delay or prevent the onset of sea breeze conditions.  Low pressure systems passing offshore create winds from the southeast.

Current Weather Conditions and Forecasts Web-link

Meteorological data is collected at Smith Point Beach at the eastern end of Great South Bay, at Brookhaven National Laboratory in the center of the island northeast of the Bay, and also at Orient Point.  This real-time data, plus plots up to the past 48 hours are available from the web-link above.  This link also provides access to local and national weather conditions and forecasts.

National Weather Service - Upton, NY

The National Weather Service located on the grounds of Brookhaven National Laboratory provides access to local and national weather forecasts, observations, and models.

Sea Conditions at Smith Point
Through funding from the Suffolk County DEC, real time data on sea level, tide, and water temperature is collected and made available by the LISHORE consortium.