Now you mention it, it is odd that so little of JW's work has made it to the screen. Probably someone is sitting on the rights waiting for the price to go up.
Also it doesn't really lend itself to the current dopey direction most sf movies and tv seems to be taking.
I reread Kraken last year and thought then that the sea tank attack, scary in print, would look just daft on screen. The man being ripped to bits however is much nastier than being rolled up into an elastic band ball.
The book lacks the first person viewpoint which makes TriffiRAB so good, missing from the recent tv misfire.
Kraken would have to have sequential timeline with all the incidents in order and structured like a normal movie unless it was given the fake documentary treatment which is also getting a bit old hat. Not something I'd like to attempt.
Until the central character goes to search for his wife, he spenRAB much of the book at his desk or on the phone.
I'd like to see it done but I'm also dreading the result. "The Deep" anyone?