Martin has not finished outside the top four once all week and deservedly takes the RS:X Boys gold medal whilst Yunxiu's consistency proved decisive as she took her nations first ever ISAF Youth Worlds gold medal in the RS:X Girls.
Host has been dominant in the Laser Radial Girls all week and has a massive 29 point advantage whilst McHardie and Wilkinson got the SL16 job done on the penultimate day of racing.
Smith and Clark were crowned 420 Girls ISAF Youth World Champions late in the day after Italy's Ilaria Paternoster and Benedetta di Salle picked up a non excludable disqualification.
Breeze and waves spoilt the sailors once again in the sun kissed Island as the Mediterranean Sea and wind offered up 16 knots with gusts up to 25 knots reported on the race course.
Hugs in abundance were the case for Martin when he reached the shore and immediately expressed his delight in taking the title, "I'm so happy man. I couldn't believe it after the last race, it took me a while and then I jumped into the water and that's when it hit me - I've won it, I've won it.
"This means everything. It's the ISAF Youth Worlds, it's the biggest youth event there is and it couldn't mean anything more to me.
"I'm going to have to wait until tomorrow night and then we're going to party."
Check out Martin after coming back ashore here.
Sitting in second, twenty points behind Martin, on 43 points is Ukraine's Oleksandr Tugaryev. The Ukrainian has won five races but ultimately he could not match Martin's consistency to keep him at bay. Nonetheless with 23 points separating him and fourth place he is guaranteed a medal. The fight for bronze is on with Radoslaw Furmanski (POL), Ignacio Berengeur (MEX) and Maayan Rafic (ISR) all able to take the final podium spot.
China's Yinxiu has an unassailable eight point lead in the RS:X Girls and takes her nations first ever ISAF Youth Worlds gold medal. Yinxiu was near perfect on the penultimate day picking up a 2-1-1 scoreline. With a race to go Yinxiu discards a sixth place meaning Marta Maggetti (ITA) cannot catch her.
Maggetti is guaranteed at least bronze as she has put America's Marion Lepert, in fourth, out of her reach. Five points separate Lepert and third place Sara Wennekes (NED) which will make for an exciting climax in the RS:X Girls.
Norway's Host followed in Siren Sundby's footsteps by taking the single handed girls dinghy title. Sundby, an Athens 2004 Olympic gold medallist in the Europe, won Byte Girls gold at Sydney 2000 whilst Host won in convincing style in Limassol with 29 points separating her and Agata Barwinska (POL) in second place with a race to go.
"I don't even have any words to describe this," said a near speechless Host immediately after racing. "I'm just so happy right now. I was trying not to smile coming in but it didn't work, I'm just really blown away.
"I'm just so so so happy - it's crazy."
Click here to see Host's elations.
The fight for the silver and bronze medal is still on with Barwinska, Monika Mikkola (FIN) and Maxime Jonker (NED) all in the mix up.
New Zealand's McHardie and Wilkinson have been dominant in the SL16 throughout the week and focused on the job at hand on the fourth day to get it done in style.
"It's awesome, absolutely great," they said. "Today we just needed to keep the Aussies behind us and be consistently in the top five and we did that so we are very happy.
"It's awesome, I'm so proud to be representing New Zealand and winning, and beating the Aussies," they said with a smile.
"It's been good competition but we've been lucky to pull some good results out."
View an interview with McHardie and Wilkinson.
Paul Darmanin and Lucy Copeland (AUS) will have to settle for silver for the second year running as they have a strong advantage over the chasing pack.
The race is on for bronze as one point separates James Henson and Oliver Greber (GBR) and Brazil's Kim Andrade and Antonio Carlos Lopes Neto in third and fourth respectively.
Italy's Paternoster and di Salle received a non-discardable late in the day and subsequently handed the title to Smith and Clark, who were expecting to have the Italians for close company on the final day.
The victory makes amends for Smith and Clark who lost out on gold to the Italians at the 2012 ISAF Youth Worlds.
Paternoster and di Salle drop to fourth on 49 points whilst Chile's Nadja Horwitz and Carmina Walsh are promoted to second on 36 points with Kimberly Lim and Savannah Siew third on 46 points.
With one race remaining across all fleets France's 29er duo of Lucas Rual and Emile Amoros can afford to finish no lower than 19th to take gold. With their worst race standing at fourth only a discarded OCS in Race 6 tarnishes their scoreline.
An OCS can prove costly, and two can make the difference between finishing on the podium or not, and that's exactly what happened to Klaus Lange and Ignacio Varisco (ARG) as they picked up their second OCS in Race 12 to drop out of the podium spots. They sit fourth on 67 points with Markus Somerville and Jack Simpson (NZL) second on 53 points and Ida Svensson and Rasmus Rosengren (SWE) third on 54 points.
Juan Perdomo (PUR) has a 16 point advantage over Joel Rodriguez (ESP) heading into the last day in the Laser Radial Boys fleet. The Puerto Rican holds a discarded OCS so will have to tread carefully in the final race.
Brazil's Tiago Brito and Andrei Knepp pulled within site of the 420 Boys gold medal as seven points split them and Portugal's Diogo Pereira and Pedro Cruz.
Discarding an eighth place the Portuguese will have to put eight places between them and the Brazilians if they are to stand any chance of taking the title. Italy's Matteo Pilati and Michele Cecchin are third overall.
The final day of racing at the 2013 Sail First ISAF Youth Worlds gets underway at 12:00 local time on 19 July.
ISAF Youth Worlds Website.