On February 5, 1999, approximately 1850 central standard time, a Bell 206-B3 helicopter, N907CA, was substantially damaged when it impacted water during final approach to a private heliport near Sabine Pass, Texas. The non-instrument rated commercial pilot, the sole occupant, sustained minor injuries. The helicopter was owned by a private individual and operated by Horizon Helicopters Inc., of Angleton, Texas. Night instrument meteorological conditions prevailed at the time of the accident and a company VFR flight plan was filed for the Title 14 CFR Part 91 positioning flight which originated from Angleton, Texas, at 1820. During a telephone interview conducted by the investigator-in-charge (IIC), the pilot stated that he called a coworker to check the destination weather at the Angleton base prior to the maintenance flight to Angleton. The pilot was told that "the weather was flyable." After arriving at Angleton, the helicopter underwent a "seven-day routine maintenance inspection" for 1.5 hours. The pilot did not get a weather briefing prior to the return flight back to home base located near Sabine Pass, Texas. According to the pilot, the weather for the flight back from Angleton was night VFR along the route until he reached his destination. The pilot "turned right on final approach at approximately 300 feet AGL, and entered some fog, became disoriented, and then impacted the water." The helicopter then rolled inverted and became partially submerged in five feet of water. Galveston Municipal Airport, which is 55 miles southwest of the accident site, was reporting the weather at 1816 as winds from 120 degrees at 10 knots, 3 statute miles visibility with mist, ceilings broken at 200 and 900 feet agl, and overcast at 4,000 feet agl, temperature and dewpoint 66 degrees Fahrenheit, and altimeter of 30.17 inches of Hg. Damage to the helicopter included a separated tail-boom and structural damage to the fuselage. The pilot had accumulated 2,455 hours of total flight time at the time of the accident, of which 650 hours were in the accident aircraft make and model. The pilot held an instrument rating in airplanes, but not helicopters.