Traveller on old ship, say, upset about Henry's mapmaker? (10)
I believe the answer is:
geographer
'henry's mapmaker?' is the definition.
I can't tell whether this definition defines the answer.
'traveller on old ship say upset' is the wordplay.
'traveller on' becomes 'rehp' (I can't justify this - if you can you should give a lot more credence to this answer).
'old ship' becomes 'argo' (I've seen this in other clues).
'say' becomes 'eg' (both can mean 'for example').
'upset' says the letters should be written in reverse.
'rehp'+'argo'+'eg'='rehpargoeg'
'rehpargoeg' reversed gives 'GEOGRAPHER'.
'about' is the link.
Can you help me to learn more?
(Other definitions for geographer that I've seen before include "Person studying the physical aspects of the earth" , "Student of Earth's features" , "Mercator?" .)