Complex sentence: To date, no one is sure of what happened to John Coxon or his ship, but several accounts, including those of his crew's, stated that his ship weighed around eighty tons and was equipped with eight guns.
Split into simpler sentences: To date, no one is sure of what happened to John Coxon or his ship. But several accounts, including those of his crew's, stated that his ship weighed around eighty tons and was equipped with eight guns.