Iran covets its well-deserved reputation for sponsoring state terrorism.
Tons of photos here of Swimmer Delivery Vehicles (SDVs) similar to what I believed launched the tanker limpet attacks.
https://www.google.com/search?q=seal+swimmer+delivery+vehicle+sdv&rlz=1C1CHFX_enUS586US587&source=lnms&tbm=isch&sa=X&ved=0ahUKEwj5r4X3geniAhURRKwKHdbJDRgQ_AUIECgB&biw=2133&bih=1022