Complex sentence: Today this type of vessel, varying in size from 14 to 35 metres, is now very popular for tourist charters although, for considerations of crew economy, diesel power is now almost universally used and many are not properly rigged for sailing.
Split into simpler sentences: Today this type of vessel, varying in size from 14 to 35 metres, is popular for tourist charters. For considerations of crew economy, diesel power is now almost universally used and many are not properly rigged for sailing.