The African coast lies only ~ 313 km from Mt Teide, but this is greater than the visibility range V ~ 253 km. There are reports of Africa being visible from Fuerteventura.
Although politically they are part of Spain, the Canary Islands are closer to Africa than they are to Europe and so geographically they are part of the African continent. Fuerteventura is the closest island to Africa, situated at only a 100 km distance from the coast of Morocco.
But elsewhere, as here on La Palma, more violent eruptions build steep-sided cones with surrounding layers of thick ash. Eruptions in the past 60 years have jolted this island to the core, creating a fault line - a crack you can walk through - along the island central spine 6,000 feet above the Atlantic Ocean.