the level of competition, difficulty of the course, degree of water turbulence. and ability of the other paddlers, times can go up to 200 seconds. In international competitions (World Championships, World Cups, World Ranking Races) all competitors complete a first run in the qualification round, called the "heats"; the fastest 20 to 30 boats make it through to the semi-final. The remaining competitors complete a second run, with a further 10 moving forward. The qualifying format is different for the Olympic Games, where each competitor completes two runs and the time of their faster run gives the qualification result. Depending on the number of participants in the event, 10 to 40 boats make it through to the semi-final; this consists of one run on a different course. The fastest semi-final boats, the number determined by the number of participants, make it through to the final, where they navigate the semi-final course once more. Their ranking within the final group is based on the time of that last run alone. If the competitor's boat, paddle or body touches either pole of the gate, a time penalty of two seconds is added. If the competitor misses a gate (for the gate to be considered correctly negotiated, the whole head of the athlete (or all athletes) and at the same time a part of the boat must pass through the gate), deliberately pushes the gate to pass through, goes through the gate in the wrong direction or upside-down, or goes through it in the wrong order, a 50-second penalty is given. Only one penalty can be incurred on each gate, and this will be taken as the highest one. There are currently four Olympic Medal events: C1 (canoe single) Men C1 (canoe single) Women C2 (canoe double) Men (was dropped after 2016) K1 (kayak single) Men K1 (kayak single) Women Kayak cross Men (to be added in 2024) Kayak cross Women (to be added in 2024) In the 1960s and early 1970s, boats were made of heavy fiberglass and nylon. The boats were high volume and weighed over 30 pounds (14 kilos). In the early 1970s Kevlar was used and the boats became lighter as well as the volume of the boats was being reduced almost every year as new designs were made. A minimum boat weight was introduced to equalize competition when super light materials began to affect race results. The ICF