Big wave surfing
Big wave surfing is a discipline within surfing in which experienced surfers paddle into , or are towed into , waves which are at least 20 feet ( 6 . 2 m ) high , on surf boards known as "guns" or towboards . 
<triplet> Big wave surfing <subj> surfing <obj> subclass of <triplet> surfing <subj> surf board <obj> uses <triplet> surf board <subj> surfing <obj> sport