Complex sentence: Phase II consists of Royal Navy logs from a similar time (1912-1925) to those digitised in Phase I. In addition to the newly introduced Phase II logs, there are extended logs of ships from Phase I being transcribed at present.
Split into simpler sentences: Phase II consists of Royal Navy logs from a similar time to those digitised in Phase I, 1912 to 1925. There are extended logs of ships from Phase I being transcribed at present.