▁cla p ▁sk ates . ▁ ▁Both ▁traditional ▁and ▁cla p ▁sk ates ▁use ▁long ▁and ▁straight ▁bl ades ▁compared ▁to ▁many ▁other ▁ice ▁sk ating ▁sports . ▁Bl ades ▁are ▁about ▁ 1   mm ▁thick ▁and ▁typically ▁come ▁in ▁lengths ▁from ▁. ▁Most ▁compet itive ▁athlet es ▁use ▁lengths ▁between ▁, ▁depending ▁on ▁body ▁size ▁and ▁personal ▁preference . ▁The ▁Vik ing ▁sk ating ▁factory ▁in ▁Holland ▁still ▁counts ▁as ▁the ▁world ' s ▁biggest ▁and ▁innov ative ▁producer ▁of ▁cla p ▁sk ates . ▁ ▁A ▁lot ▁of ▁attention ▁is ▁given ▁to ▁air ▁resistance . ▁The ▁rules ▁demand ▁that ▁the ▁su its ▁follow ▁the ▁natural ▁shape ▁of ▁the ▁body , ▁prevent ing ▁the ▁use ▁of , ▁e . g ., ▁drop ▁sh aped ▁hel m ets ▁( as ▁seen ▁in ▁cy cling ) ▁or ▁more ▁invent ive ▁" Donald ▁D uck " ▁cost umes . ▁However , ▁a ▁lot ▁of ▁time ▁and ▁money ▁is ▁spent ▁developing ▁fab rics , ▁cut s ▁and ▁se ams ▁that ▁will ▁reduce ▁drag . ▁Some ▁sk aters ▁use ▁low ▁( no ▁th icker ▁than ▁ 3   mm ) ▁" a er od ynamic ▁stri ps " ▁attached ▁to ▁their ▁su its . ▁These ▁are ▁intended ▁to ▁create ▁tur bul ent ▁flow ▁in ▁certain ▁areas ▁around ▁the ▁body . ▁ ▁G lass es ▁or ▁g og g les ▁may ▁also ▁be ▁worn ▁so ▁that ▁the ▁wind ▁does ▁not ▁dry ▁out ▁the ▁eyes . ▁ ▁Compet ition ▁format ▁ ▁All round ▁ ▁The ▁oldest ▁competition ▁format