他們兩位坐船頭
They were both at the top of the boat.

Cantonese Sentence Breakdown

他們 taa1 mun4
they
兩 loeng5
two
both
some
a few
tael, unit of weight equal to 50 grams (modern) or 1
16 of a catty 斤jīn [斤] (old)
a group of about ten people
位 wai6
position
location
place
seat
classifier for people (honorific)
classifier for binary bits (e.g. 十六位 16-bit or 2 bytes)
throne
post
rank
status
坐船 co5 syun4
to go on a boat
頭 tau4
head
hair style
the top
end
beginning or end
a stub
remnant
chief
boss
side
aspect
first
leading
classifier for pigs or livestock M: 个gè [个]
used as a suffix
an area
a location