Blue Grotto from Sorrento

I was getting ready to recommend Giannis Boat tour, and I found this description on a previous forum post. We took the ferry over from Sorrento and met Capt Nicola at the dock, but Gianni is very responsive and you could ask him about a different pickup option. We were fortunate that the winds calmed and there was no line for the Grotto. It’s never guaranteed.
https://community.ricksteves.com/travel-forum/italy/best-boat-tour-of-capri-this-coming-week

We were fortunate that the winds calmed and there was no line for the
Grotto. It’s never guaranteed.

That's your issue, Lin. Access to the grotto is weather dependent. As well, you might want to read the details provided from the Capri website:

https://www.capri.com/en/e/la-grotta-azzurra?srsltid=AfmBOoqekXm2koxgg59VspoxPp6coEaRk-w2dg68OgTS6LdM87VCnjr1

I did the Blue Grotto and it was great.

I did a boat tour with Lubrense Boats at the end of May 2022. We entered the blue grotto after transferring to a local guide row boat which was waiting in a bay just outside the grotto. We got back in our boat and went part way around Capri island to Porto Marina Grande. We got off and visited Anacapri and Monte San Michele on our own. We returned to our boat and circled more of the island. We stopped for a quick swim, then went through a natural stone arch in the ocean. Then back to our starting marina. Professional crew, a light lunch and soft drinks included. You could stay on the boat or hang out at the Marina Grande beach instead? I enjoyed the experience.

There are numerous boat operators at the Capri harbor that offer both "round the island" tours and just straight to the blue grotto options. So you could wait til the evening before when you know the next day's weather is good, have your Sorrento innkeeper help you find the best ferry option time-wise and then head over to Capri on that ferry the following day.

Then you can walk up and buy your ticket for the Capri/Blue Grotto Boat. They are loading and going constantly.

The later you go, the more the line of boats builds so earlier is better. Since it's August, I think you'll have good light in the Grotto even early in the day.

Chris, will the Sorrento harbor have the same offerings of tours? That is where our cruise ship will drop us. I would prefer to go to the Blue Grotto directly from Sorrento without having to take the ferry over to Capri to book the tour as you described from Capri.
We will have spent the night anchored at Sorrento and then leave at 5 PM on the second day there. My problem is that I do not know what time I can get the tender into Sorrento on the second morning. We arrive the first day at 3 PM and feel sure the Blue Grotto line will be very long or the Grotto will be closed completely because of water level at that time of the day. The cruise ship does not offer this as a ship excursion.

Many thanks to all who have helped me with this question!

It's quite possible that there are enterprising Italians who know there's a cruise ship arriving and have arranged to do package tours to the Blue Grotto. But in all likelihood, it'll work just like I described anyway... Large ferry to Capri, then smaller excursion boat to the Grotto, then you wait in line for the rowboats.

I'm not sure what you mean about the water levels on your arrival day. Have you checked tidal charts for that day and time?

And I will add that the Blue Grotto is IMO, just kinda okay as a destination. It is kind of a fun experience because of the kitsch, but I think the fun would fade very quickly if you were boat #20 in line at the cave entrance. Honestly don't make this your absolute bucket list thing. It's really not worth it, and there is a decent chance the weather won't cooperate anyway. Whatever your Plan B is will be fantastic

....or the Grotto will be closed completely because of water level at
that time of the day.

The sea isn't tidal so if they close access to the cave, it would be because of wave activity/rough seas and not water level.

I'll agree with Chris' take on the thing: we skipped it due to just too many negative reviews about long lines, being hassled for tips, rude boatmen, the very short amount of time in the thing - if you can even get into the thing - for the time and $ involved, etc. Really, given the risk of being stuck in a bobbing boat for a long period of time before even transferring to a tiny rowboat (read the complaints from seasick tourists), getting out there and not being able to do it all, or having far inferior an experience than what you're anticipating, a Plan B is advised for the short amount of time you have.

Understanding that while certainly not everyone has had a poor experience with the Grotto, you might want to scan the reviews? The number of issues people had reported were enough for us to find other things to do.

https://www.tripadvisor.com/Attraction_Review-g488299-d195537-Reviews-Blue_Grotto-Anacapri_Island_of_Capri_Province_of_Naples_Campania.html

What have you done previously in Sorrento or on Capri?

Your comments re Plan B so noted, Chris and Kate. I have about decided that a cruise around Capri will do us and if the BG happens then hooray, but if not, that will be okay. We took the lift to the ??, spent sometime up there as views were great and then hiked down into the town and spent time there. I would be open to suggestions for Sorrento, having been there twice and looking for something else to do for a couple of hours.

Again, thanks!

Sorry for the late reply, Lin -
This:

We took the lift to the ??, spent sometime up there as views were
great and then hiked down into the town and spent time there.

I'm guessing you took the chairlift in Anacapri to the top of Mt Solaro. As you'd mentioned having done some hiking before, I'll recommend another couple of nice ones on the island?

This one to the ruin of a Roman villa. It provides another great view! The way there is pretty much uphill (but certainly not steep the entire way) but what goes up, must come down, eh? Wear comfy shoes and a hat, bring water, and rest when necessary.
https://www.capri.com/en/e/villa-jovis-mount-tiberio?srsltid=AfmBOoqTPW10tCa8Mmr64eSq7_u5lYSZ9rLpDjmpgw6FtWyxLRrF-SME

Near the ruin is a little cafe for rehydrating and has another nice view:
https://www.tripadvisor.com/Restaurant_Review-g187783-d2298236-Reviews-Bar_Jovis-Capri_Island_of_Capri_Province_of_Naples_Campania.html

A little easier is this one:
https://www.capri.com/en/e/arco-naturale-and-pizzolungo
You can skip the stairs to Grotta di Matermania if desired.

Thanks to all!