UnScramble this Word: p e c d l a e m?

Questions

What is the underwater equivalent of radar?

What is the connection between Sandwich,Dover,Hythe,Hastings and Romney?

Which Fletwood Mac album cost $1 million to produce in 1979?

Which eminent French novelist defended Dreyfus when he was accused of betraying military secrets?

Which radio and TV presenter made the hit parade in 1978 with a version of the Cornish Floral dance?