"5. Observations and Summary
5.1 Ocean Temperature Record before 1960/70
Trying to extract an ocean heating record and trend lines during the times of bucket and early engine inlet readings seems a futile undertaking because of vast systematic and random data error distortion.
The bucket water readings were done for meteorological purposes only and
a. without quality protocols and with possibly marginal personnel qualification
b. by many nations, navies and merchant marine vessels
c. on separate oceans and often contained within trade routes
d. significantly, scooping up only from a thin surface layer
e. with instrumentation that was far cruder than the desired quality
f. subject to wide physical sampling variations and environmental perturbances
Engine inlet temperature data were equally coarse, due to
a. lack of quality controls and logging by marginally qualified operators
b. thermometers unsuitable for the needed accuracy
c. subject to broad disturbances from within the engine room
d. variations in the intake depth
e. and again, often confined to specific oceans and traffic routes
The engine inlet temperatures differed significantly from the uppermost surface readings,
a. being from a different depth layer
b. being more stable than the diurnally influenced and solar heated top layer"