Boat racing is a sport in which boats, or other types of watercraft, race on water. Boat racing powered by oars is recorded as having occurred in ancient Egypt, and it is likely that people have engaged in races involving boats and other water-borne  craft for as long as such watercraft have existed.
regatta is a series of boat races. The term comes from the Venetian language, with regata meaning "contest" and typically describes racing events of rowed or sailed water craft, although some powerboat race series are also called regattas. A regatta often includes social and promotional activities which surround the racing event, and except in the case of boat type (or "class") championships, is usually named for the town or venue where the event takes place.
Although regattas are typically amateur competitions, they are usually formally structured events, with comprehensive rules describing the schedule and procedures of the event. Regattas may be organized as championships for a particular area or type of boat, but are often held just for the joy of competition, camaraderie, and general promotion of the sport.
One of the largest and most popular rowing regattas is the
Henley Royal Regatta held on the River Thames, England. One of the largest and oldest yachting regattas in the world is Cowes Week, which is held annually by the Royal Yacht Squadron in Cowes, England, and usually attracts over 900 sailing boats. Cowes Week is predated by the Cumberland Cup (1775), Port of Dartmouth Royal Regatta (1822) and Port of Plymouth Regatta (1823). North America's oldest regatta is the Royal St. John's Regatta held on Quidi Vidi Lake in St. John's, Newfoundland every year since 1818.
The term "regatta" is from
Venetian regata ("contention for mastery"), from regatare ("compete, haggle, sell at retail"), possibly from recatare.
There exist other traditional and centuries old boat races like
Vallam kali of Kerala, India and Dragon Boat Race from China.
Rowing, by Lucien Davis, 1898.
World Rowing Federation championship events
American Henley Regatta, first world championships in the United States
Dad Vail Regatta, Philadelphia, Pennsylvania, championships for college clubs The
Harvard–Yale Regatta – also known as 'The Race'
Head of the Charles Regatta, on the Charles River between Boston and Cambridge, Massachusetts
Head of the Hooch, on the Tennessee River in Chattanooga, Tennessee
Intercollegiate Rowing Association National Championships, college championships for men and lightweight women
Marathon Rowing Championship a continuous 42.195-kilometre (26.219 mi) rowing regatta on Cane River Lake in Natchitoches, Louisiana
New England Interscholastic Rowing Association Championships
Poughkeepsie Regatta was an historical regatta that hosted the IRA National Championship from 1895 until 1949.
Scholastic Rowing Association of America Championships
USRowing National Championships The Windermere Cup - between the University of Washington and one or several challengers of their choice
The Brentwood Regatta is held in the spring and is one of the largest high school rowing regattas on the west coast of
Royal Canadian Henley Regatta, in St. Catharines, Ontario, Canada, in the first week of August is one of the largest annual regattas in North America, attracting hundreds of clubs in 128 junior, senior, and master's events. Royal St. John's Regatta, held every year on Quidi Vidi Lake in St. John's, Newfoundland, North America's oldest annual sporting events.
Sailing race events are typically held for a single
one design class and usually last more than one day. Regattas may be hosted by a yacht club, sailing association, town or school as in the case of the UK's National School Sailing Association and Interscholastic Sailing Association (high school) regattas or Intercollegiate Sailing Association (college) regattas.
Barcolana regatta of the yacht club Società Velica di Barcola e Grignano is currently the Guinness world record holder as the "largest sailing race" with 2,689 boats and over 16,000 sailors at the starting line. Currently, The Three Bridge Fiasco, conducted by the Singlehanded Sailing Society of San Francisco Bay with more than 350 competitors is the largest sailboat race in the United States.
Oldest sailing regattas
1775 – Cumberland Cup, organised by the
Royal Thames Yacht Club, UK 1777 – Lough Ree Regatta, organised by Athlone Yacht Club, Ireland.
1792 – Whitstable Regatta UK
Port of Dartmouth Royal Regatta, Dartmouth, UK 1823 – Port of Plymouth Regatta,
Plymouth, UK 1826 –
Cowes Week, Isle of Wight, UK 1828 – Kingstown Regatta, (now renamed Dun Laoghaire), Ireland
 1828 – Royal Harwich Regatta,
Harwich, UK 1834 – Lough Derg Regatta, at Killaloe, Williamstown and Drumineer, Ireland.
 1837 –
Sydney Australia Day Regatta, held every year since 1837, the longest running without a break 1838 –
Royal Hobart Regatta, Australia 1840 –
Auckland Anniversary Regatta, New Zealand 1844 – Royal Geelong Regatta / Audi Victoria Week,
Royal Geelong Yacht Club, Australia 1845 –
New York Yacht Club Regatta, United States 1849 –
Pass Christian Regatta Club on July 21, 1849; twelve boats participated. First regatta on the U.S. Gulf Coast 1849 – Sandy Bay Australia Day Regatta Australia
Race to the Coast, Southern Yacht Club Regatta. Oldest continuously running regatta in the Western Hemisphere United States 1851 –
America's Cup, usually competed for in the country of the current defender/holder 1851 – Port Esperance Regatta, Australia
1856 – Chester Race Week,
Nova Scotia, Canada  1857 – Gorey Regatta, Jersey, Channel Islands
Kiel Week, Kiel, Germany 1885 – Appledore & Instow Regatta, North Devon, UK
1886 – Torbay Royal Regatta,
Torbay, UK 1894 – Britannia Boating Club, Ottawa, Ontario, Canada
Current sailing regattas
Aegean Rally, Aegean Sea, Greece
America's Cup, hosted by prior winner The Athlone Yacht Club Regatta on Lough Ree, Ireland
 Appledore & Instow Regatta
– founded in 1885, tracing its origins back to 1831, is held annually on the River Torridge between the Villages of Appledore & Instow North Devon, UK. 
Auckland Anniversary Regatta held annually on the Waitemata Harbour to celebrate Auckland Anniversary Day Balaton Regatta, held every year on the Lake Balaton between the teams of Veszprém Campus and Keszthely Campus of University of Pannonia
Balmain Regatta held annually on Sydney Harbour, Australia
Barcolana Autumn Cup Regatta, one of the largest single start sailing regattas in the world, held annually on the second Sunday of October in  Trieste, Italy Bass Week,
Bassenthwaite Lake, Cumbria Bay Week,
Block Island Race Week, Rhode Island
Canada's Cup, held periodically on the Great Lakes.
Canadian Olympic-training Regatta, Kingston (CORK) held annually in August in Kingston, Ontario Canada. Carriacou Regatta Festival, Hillsborough, Carriacou, Grenada. W.I. - First weekend in August each year.
CASON Grand Prize Solo Regatta,
Lake Balaton, Hungary, held annually in September. Charleston Race Week,
Charleston, South Carolina, held each April for three days, with races staged both in Charleston Harbor and offshore. Chester Race Week, Chester, Nova Scotia, Canada, 15 keelboat fleets race for 4 full days on 5 courses in mid-August on beautiful Mahone Bay
Chicago Yacht Club Race to Mackinac, held annually in July, starting in Chicago on Lake Michigan and ending at Mackinac Island on Lake Huron. Columbus Day Regatta, Miami, Florida, annually in October.
Chichester-Cowes Challenge, held annually at the end of June on the
Solent, and welcomes only classic wooden boats, mainly built in the 1920s–1930s.  The
Clipper Round the World Yacht Race Cork Week, Cork, Ireland. Hosted by the Royal Cork Yacht Club bi-annually.
Cowes Week, Royal Yacht Squadron, England
Dun Laoghaire Regatta, Ireland, combined Dun Laoghaire Yacht Clubs, held Biannually.
Færderseilasen, Royal Norwegian Yacht Club (KNS), from Oslo to Horten via Færder lighthouse. The
Figawi Race, Hyannis, Massachusetts Fowey Royal Regatta,
Fowey Cornwall annually in August  Hangon Regatta, an annual event in the city of
Hanko, Finland, infamous for attracting large groups of partying youths with a tangential interest in the sailing itself Harvest Moon Regatta,
Lakewood Yacht Club in Seabrook Texas hosts cruisers regatta during full moon in October each year from Galveston to Port Aransas 
Kamer 2 Sailing Marathon, Kaag, Netherlands, annually in September Key West Race Week,
Key West, Florida Kékszalag, Balatonfüred, Hungary annually in July
Kiel Week, Kiel/Germany - the largest sailing event in the world Lake Ontario 300,
Port Credit, Ontario - the longest fresh-water sailboat race in the world, held annually in July Larchmont Race Week,
Larchmont Yacht Club, New York Lighthouse Regatta, Lake Hefner hosted by the Oklahoma City Boat Club
Long Beach Race Week, Long Beach, California
Louis Vuitton Trophy, a world series of regattas, multiple locations
Lysekil Women's Match, Lysekil, Sweden, annually in August Mardi Gras Race Week,
New Orleans Yacht Club, large One Design regatta held on Lake Pontchartrain MidsummerSail, annual sailing regatta from the southernmost to the northernmost point of the Baltic Sea
Monsoon regatta Monsoon Regatta India
Mrduja Regatta, an annual regatta held in the city of Split, Croatia
National Offshore One Design (NOOD) New World Regatta, held every year between the ports of Koper, Slovenia and Baltimore, Maryland.
Port Huron to Mackinac Boat Race, Mighigan
Port of Dartmouth Royal Regatta, held annually at the end of August over three days on the River Dart.
Race to the Coast, Southern Yacht Club, New Orleans, Louisiana to Gulfport, Mississippi Regatta Vava'u held annually in Vava'u, Kingdom of Tonga in September
Rotary Club of Sydney Cove Charity Regatta held annually since 1995 on the second Friday of November at the Cruising Yacht Club of Australia
Round Texel, Texel, Netherlands, annually in June
Sail Melbourne, Held annually on Melbourne's Port Phillip Bay Sawadee.com Regatta Samui, Thailand, Annually on the island of Koh Samui, Thailand in June
Sint Maarten Classic Yacht Regatta,
Sint Maarten, held last weekend of March Sint Maarten Heineken Regatta,
Sint Maarten, annually in March
Sugar Bowl Regatta, New Orleans Yacht Club, New Orleans, Louisiana
Tall Ships Race
Tjörn Runt, Tjörn, Sweden, annually in August
Travemünde Week, Travemünde, Germany, annually in July United Sailing Week, Croatia. The biggest sailing regatta and yachting event in Croatia. 50 boats in 4 classes and 500 participants.
Velux 5 Oceans Race – a round-the-world, staged, single-handed yacht race; originally known as the 'BOC Challenge', and then the 'Around Alone' The
Vendee Globe – a round-the-world, non-stop, single-handed yacht race
Vintage Yachting Games, each time in another country first in 2008, Medemblik, The Netherlands since then every four years. 2012 Lake Como Italy
Voiles de Saint-Tropez, Saint-Tropez, France, annually in October The
Volvo Ocean Race Washington's Birthday Regatta, at the
Barnacle Historic State Park, Coconut Grove, Florida, annually in February
West Highland Yachting Week, Oban, W Coast Scotland Whale of a Sail, Carlyle Sailing Association, Carlyle, IL
Whiskeytown Regatta, Whiskeytown Lake—Redding, CA
Youngstown, New York Chichester Biarritz Challenge, Chichester, England, to Biarritz, France, annually in April. 
School sailing regattas
Mallory Cup, United States high school sailing national championships.
Nixor College, the first college in Pakistan to launch a 'RAFT' regatta for team building.
Royal College Colombo and S. Thomas' College, Mt. Lavinia, Oldest Regatta in Sri Lanka. ( Royal Thomian Regatta)
Sywoc, the Student Yachting World Cup organized by the students of the École Polytechnique. The NSSA National Youth Regatta is the largest dinghy sailing regatta and the largest youth sailing regatta in the UK. Due to its size the NYR visits a new location each year alternating between coastal and inland venues. Previous years venues include Bridlington (North Yorkshire), Datchet Sailing Club (West London) Plymouth (Devon), Redcar (North East England), Deal (Kent), Grafham Water (Cambridgeshire), Weymouth (Dorset) to name just a few.
University / college sailing regattas
Charleston Open, College of Charleston Fisher Hall Regatta,
University of Notre Dame
Intercollegiate Sailing Association National Championships, various locations Kennedy Cup,
US Naval Academy The Roth Regatta, Roth Pond,
State University of New York at Stony Brook The Regent Regatta, Regent Pond,
Regent University The CoEP Regatta, Mula River,
College of Engineering, Pune - Held annually in March (since 1928), one of the oldest and most celebrated regattas in India Mustang Open Regatta, Cal Poly San Luis Obispo
A boat race seen from the International Space Station, 2006