Pontoning or Pontooning: How To spell?
The word Pontoning is misspelled against Pontooning, a noun meaning "The act, art, or process of constructing pontoon bridges."
Pontooning has double "oo" is mispronounced as "o"Remember double 'OO' in between the strings pont & ning which should not be misspelled with single 'O'
Wrong Spelling:  pont-o-ning  Correct Spelling:  pont-oo-ning 
Find more incorrect spellings of Pontooning to spell right way.