A warm 50 is easy to pull start.
I had low water in a cell of my battery a few years ago, started fine but an evening on the bass drifts soon flattened it (ESP with bait pump running).
So, I pull started it for every drift, probably 15 times!
Starting a cold one, would be a different story I imagine.
If in doubt, carry a charged jump pack (I used to and only ever used it to start someone's car that was blocking the slip!).