There are some very nice drawings and observations here for Messier 51 AKA the Whirlpool Galaxy.

Last night at 22:30hrs (UT) I was looking at M51 through my C9.25 XLT Fast Star and 2" Skywatcher LPR filter and TS 2" prism diagonal.
Here in Cheshire - England. We had an unusually clear night. It was very transparent, with excellent seeing. ANT I, I estemated the NLM at +4.3.

Messier 51 is now riding high at the Zenith. So I have very little atmosphere to see through.

24mm Panoptic X 97. Bright and stellar with NGC 5195 also visible though fainter.

I then boosted the magnification to x180- Baader 13mm Hyperion. M51 was faint at first. But I could now see faint dust lanes with averted vision when my eye had settled and adapted to the darker field.

Switching to my older 35mm Celestron Ultima (x67)
M51 looked like a galaxy should look. The arms were clearly visible with averted vision. And NGC 5195 was also more defined.

This eyepiece gave me the best view of M51, that I have had.