The Man who Missed the War (Lost World series)

When German submarines were sinking so much Allied shipping that Britain faced the danger of starvation, Dennis Wheatley – then a member of the War Cabinet's Joint Planning Staff – suggested that a system of raft convoys, moved by the Gulf Stream and prevailing winds, should be used to float essential supplies across the Atlantic. This story is based on that idea.

Philip Vaudell leaves the United States on a solitary raft, but when he comes across a ploy that would put him in danger, he casts away from his crew and the raft is left in the lap of the gods.
But, with Philip was the other real trouble – in the enticing shape of red-headed Gloria, who had stowed away on his raft.

Instead of drifting into European waters, they are carried down to the Antarctic where, amidst its eternal snows, he discovers a large area with a warm climate and populated by a lost race. Will they be able to make contact and request rescue, or will they be forced to find a way to integrate with these people? Furthermore, will they be welcomed, or used as part of their ritual human sacrifice?