Complex sentence: An unarmoured flight deck was agreed upon in June by the Controller of the Navy and the Fifth Sea Lord and the new design, long at the waterline and known as Design X, was submitted to the Board on 10 August although it was not approved.
Split into simpler sentences: An unarmoured flight deck was agreed upon in June by the Controller of the Navy and the Fifth Sea Lord. The new design, long at the waterline and known as Design X, was submitted to the Board on 10 August, although it was not approved.