>> i think everybody was on edge because it had rained the night before. >> reporter: chris jewell isastic, jewel is taking part in his very first rescue mission. >> so, the visibility throughout the whole operation was really, really poor. >> reporter: together with two other brits, collectively dubbed the "awesome foursome," they will attempt to finish off a dramatic three-day cave rescue as the world watches. >> these u.k. divers and the european divers, these were all by-name requests -- to come in and do this. >> reporter: they better hurry. heavy rains are threatening to scrap the plan. >> i mean, i think that not just my head, like, everybody's head was like, "hey, we're not gonna be able to continually execute the way we did on day one and day two, if these rains really start coming." >> reporter: the weather is one obstacle. the number of people that still need to come out of the cave -- another. four boys, one coach and four thai military members are still inside. >> on day number three, we had to bring out an extra person. so, in order to do this, jason mallinson swam throu