I think that at the moment, the technology won't work for most people. The DC rapid chargers available here in Europe are 50kW and I think that the non-Tesla ones are the same in the US. The Tesla superchargers are 120kW and I don't know how much they cost to install but a 50kW rapid charger costs anywhere between £50,000 and £100,000 to install here in the UK depending on location but we are talking about areas like motorway service stations, not a lakeside - I suspect it would be way over £100,000 at many lakes because of the amount of cabling required.
A 50kW rapid charger takes over 2 hours to fully charge a 100kW/hr Tesla battery, so if you have to stop skiing every 8 - 10 sets and then have a 2 hour delay to recharge, I don't see anyone paying an extra 100k on top of the boat for that privilege.
I think there will need to be a pretty dramatic upgrade in this technology for electric boats to be a practical proposition for the majority of users. Electric cars have ranges of 80 - 300 miles when fully charged. This is more than the average daily mileage for the vast majority of people so an overnight, slow charge approach is ideal. Tow boats have a completely different usage pattern.
If, however, you had a boat which got used one day a week for a limited number of tows (less than 10), then the idea of solar panels would come in to play - you could slow charge for "free" over several days. There is, however, a limit on how much energy the sun delivers per square foot of planet earth so no matter what improvements come along in solar or battery tech, it would not be possible to charge quickly without huge solar arrays. You will never see cars being run from photo cells on their roof - it isn't possible.
I'm not down on electric vehicles - I drive one every day and think electric cars are absolutely the future. I just think it will be a long time before this tech makes sense for the majority of water skiers