I do not get anything out of this but, please do check out,
http://anastasia.travel/, you will have the perfect time in STB.
I used them on two X two day tours in STB, from the Magic, you see more, do more, thry are like a concierge service, you do not need Russain visas, but thry will get you tickets that allow you through immigration at STB. You have to either,
1/ book with
DCL to get off at STB.
2/ book with an authorised Russian tour agent like
http://anastasia.travel/.
3/ or get a visa to get off.
In 2010 and 2015 many of my friends took my advice, thry all thought the tours were excellent and tailor made. For a family it's often cheaper than DCL and you can add evening touring without going back to the ship. You can add places extra that DCL doesn't go to, see my trip report.
We went through immigration in minutes each way, every day no issues and was personally met by CEO Anastasia to ensure 100% satisfaction with guide, car and driver, and met her en route and at the end as well. They provided parks even umbrellas we eat at local Russia places, went on thier trains and hydrofoils.
I recall a poster who went on a DCL tour say, " I spent EVEVEN hours looking at the inside of the bus", you can get your own private car/ van and everyone gas a window seat, the vehicle was modern and can go down smaller roads in James and had local STB decals that are safer than coaches stuck to main roads with signs saying
Disney Cruise Line.
If you email them, Katherine there often emails back within hours and will tailor make your trip for you.
I am passionate about it as STB is a wonderful city, your going to it, ensure you have a fantastic time there.