You can do away with navigation lights at night for two reasons 1. You will probably "glow in the dark" and 2. You may not be around to worry about it.
On a more serious note, lighting strikes on cats are not a common occurrence (although it does happen) and of the two times over 45 years of continuous sailing that I have been witness to such an event, both sailors came away "shaken" but relatively unharmed otherwise. Their masts on the other hand were "history".
The mast to the water "seems" to create a good "conduit" for the lightening to travel without causing an enormous amount of peripheral damage.
The two times that I witnessed actual strikes on cats, at both times the skippers had their aluminium tiller extensions trailing in the water which could have created an “earth” for the lightning. There is a lot of conjecture that when a cat is NOT “grounded” the mast acts as a repellent to any strike as the charge emanating from the top of the mast is the same as that of the lightning and repels it (or visa versa). I tend to agree with the hypothesis, as I have witnessed many, many, times cats sailing when there have been many strikes on the water around them but with no direct “hits” to the cats.
Carbon fibre boats and mast are a little disconcerting to me now though as carbon is such a very, very, good conductor of electricity.