First of all, I agree with the others, sea shanties are best sung unaccompanied. I did work out chords for a couple of shanties for a challenge on the ukulele underground forum, but I never used them. The chords themselves were OK, it just didn't sound right singing the shanties accompanied.

Now to the OP's original request. I think she's making a mistake common among ukulele players, especially novices, of confusing the actual chords with the fingering required to make those chords on a ukulele or guitar. That's not transposition. Transposition is changing the chords to sing in a different key, usually because it sits better with your voice than the key given in your source.

I commonly get chords off guitar sites, no problem. If the chord in the song says C, you play a C chord which on a ukulele is 0003. It doesn't matter what fingering you need for a guitar, you play a ukulele C. If the site/book has chord diagrams for guitar, you ignore them. Just have a sheet or book of ukulele chord diagrams to hand and use those. If it says C#dim on the song, then look up C#dim in your ukulele chord book and use that shape, not the guitar shape given.