Yes, you can. There are a few online outlets that will rent luggage out - search around for them. For instance, rentluggage.com.
You can rent a luggage rack for your trip from car rental companies or specialty luggage rental services.
I do not know of any such car. Minivans and SUVs have a small amount of luggage room in the back, but not enough to stow luggage for 8 people. Your best bet is to rent a passenger van (make sure it has luggage space in the back -- not all of them do -- or have the agency remove one of the bench seats). The alternative is to rent multiple vehicles.
It depends on why you need to rent it. If you are going on a trip with a lot of luggage, you need a big car or van. If you are alone, you can get a little one. So, it really matters WHY you need it.
You can find a car top luggage carrier rental for your upcoming trip at car rental companies, outdoor equipment rental shops, or online rental platforms like Turo or Rent-A-Car.
I don't know if snorkel gear can be rented at Hilton Head. I always take my own because often times the gear you rent will be wore out. Good snorkel gear isn't that expensive and it packs well into luggage. Take your own mask and snorkel at least, you will be glad you did. Rent fins would be OK.
luggage
Yes you can put a skateboard in a luggage that is not a carry on.
She had her luggage packed immediately. The airline lost our luggage.
Yes, you can typically leave your luggage at the hotel's luggage hold before checking in.
We would need to know your country so we can recommend a potential website to you. I'm sure you wouldn't want to pay any extra, expensive delivery fees.If you're from the UK, check out the official UK travel website, TripAdvisor.co.uk, for safe renting options.For US citizens, Economist.comhas some information about safe luggage rentals.Usually your hotel can recommend some local options if you get in touch with them before you travel.
Its a label you attach to you luggage.
luggage works