Here are a couple of samples from the WW1 RN logbooks imaged by the National Archives for the Met Office. The images are 300 d.p.i. full colour pdfs. Most are double pages, about 18Mb in size, some are single pages at about 10Mb. These images are Crown Copyright, reproduced by permission of the National Archives.
WG1: Data Rescue > Imaging and digitisation of historical instrumental marine and terrestrial weather observations >