A grandfather has become the oldest person to row 3,000 miles solo and unassisted across the Atlantic Ocean, raising more than 640,000 for dementia research. Frank Rothwell, 70, from Oldham, set off from La Gomera in the Canary Islands on 12 December and crossed the finish line in Antigua in the Caribbean on Saturday " reuniting with Judith, his wife of 50 years, in good time for Valentine's Day. He said crossing the finish line was a "completely euphoric moment" as he raised more than 648,000 for Alzheimer's Research UK in tribute to his brother-in-law Roger, who died with Alzheimer's aged 62 during his journey. Iceland Foods Charitable Foundation has pledged to double the first 500,000 of donations. Rothwell went on: "I felt quite emotional approaching the finish. It took six long weeks to row the Atlantic, but the challenge itself has taken over 18 months of training and preparation, so I'm very proud of what I've achieved and the unbelievable journey I've been on. The adventurer has previously spent five weeks on a deserted island for a Bear Grylls TV programme, and rowed in a boat nicknamed Never Too Old. Hilary Evans, chief executive of Alzheimer's Research UK, said: "We're incredibly moved by Frank's determination to raise 1m for dementia research. He has helped to spread awareness and inspired people of all ages to take on their own challenges. Fundraising efforts from ordinary people like Frank and his supporters provide a crucial lifeline to the progression of our research."