Spanish emergency services picked up 755 immigrants travelling in dozens of small boats and makeshift rafts across the Strait of Gibraltar on Tuesday and 227 from the same stretch of water the day before, the Maritime Safety Agency said.
The Mediterranean shipping lane is almost 15 km (9 miles) wide at its narrowest and is often used by migrants trying to get to Europe.
More than 75,000 have tried to cross the Mediterranean from North Africa in the first half of 2014, landing in Italy, Greece, Spain and Malta, the United Nations High Commissioner for Refugees (UNHCR) agency says, with about 800 people dying in the attempt.
About 10,500 children, two thirds of them unaccompanied or separated from their families, were included in those numbers, as people flee violence in Africa and the Middle East, often using unseaworthy vessels and with the help of smugglers.
The number of people trying to get to Europe across the Mediterranean is already about 60% higher than the whole of last year, the UN refugee agency said in July.
On Tuesday, some 78 boats and rafts carrying mostly men, but also 95 women and 20 under-18s, made the journey from North Africa to the south of Spain, Spanish authorities said.
The rush in the past 48 hours may be due to calm seas and warm weather. Increased security around the North African Spanish territories of Melilla and Ceuta is also likely to have pushed people to the coasts, local Spanish media said.
More than 700 people tried to scale the razor-wire barriers in Melilla on Tuesday, the government said, of which only 30 reached Spanish territory where they will be either repatriated or sent to the mainland Spain.