Waves were once regarded as limited to about 25 meters in height. The limits have now been eliminated. Pain was once thought to be manageable with a strong will. What this idea is based on is very hard to determine, beyond the assumption that Nature would make it so, would have to make it so. The idea that it was up to man, not Nature. to limit pain arrived only recently.
Until rather recently, it was considered scientifically accurate that a rogue wave above 30 meters in height occurs once in ten thousand years. (See eg. http://www.esa.int/esaCP/SEMOKQL26WD_index_0.html)
This was based on a study of waves, weather, currents, etc. It was also assumed to be true that rogue waves near twenty five meters in height occur only in areas of intense currents, such as the Agulhas off the West Coast of Africa or where the Gulf Stream meets the Labrador Current. These “scientific” assumptions are now known to be worth nothing, thanks to the European Space Agency