. >> reporter: surfers want to challenge themselves here in nazare?>> this is the proving ground when it comes to a team. much more about teamwork here. you need somebody with a jet ski to watch over you. and once it gets over 60 feet, g themselves and their s he >> reporter: it's dangerous even for the jet skiers. >> oh, it's almost more dangerous because you've got this big machine all of a sudden, the wave lands on you and you're stuck with the machine. >> reporter: last november mcnamara was riding a jet ski, towing his friend british surfer andrew into this massive wave. it didn't go as planned. >> oh! [ bleep ]. this thing literally exploded like a bomb, and he flew in the mid-air like a cannonball. he was a human cannonball. >> reporter: he was in the wrong spot on the wave and had to jump off his board. he disappeared momentarily before being thrown forward like a rag doll. he landed hard on the water and broke his back. >> the shock went through my back. it was like hitting concrete. >> reporter: he was rescued and brought onto the beach. he