kshelleby:

When we got back to Miami today I went to a customs agent and told him I am traveling with my boyfriend, we have 10 litres of liquor and very few souveniers (spent less than $200 total for all our shopping). He said since we did not exceed the $800 limit then we do not owe any duty or tax even though we were WAY over the limit on alotted alcohol.

The agent gave you a break.  He has the authority to do that, but technically he was incorrect and it's going to be misleading to others to describe it as anything other than being given a break.

You are allowed to bring in, according to US Custom Regulations, 1L of alcohol per person 21+ [2L per if your itinerary includes certain US Territories such as the USVI and P.R.].  Excess liquor can be charged "duty", regardless of the dollar values involved.

Can be.  Not always will be.  There are many stories here about long lines at arrival Customs waiting to pay $1.21 [or whatever] per excess bottle and Customs agents asking for those who have fewer than five excess bottles to step out of line -- Customs Agents have a tolerance for triviality, too.

You lucked out.

I plan on shopping for my liquor onboard.  Usually the duty free prices are very comparable and sometimes cheaper on the ship.  Add to that the convenience of not carrying bottles around and it seems to be a no brainer.   

Jeff and Dawn:

Add to that the convenience of not carrying bottles around and it seems to be a no brainer

Many places on Cayman will deliver to the ship if you buy it before x-o'clock.  [Time depending on when your boat leaves port.]

In that case, if I was out shopping anyway, I would take advantage of that deal.

We went to S. Caribbean last Nov. and brought back 9 bottles + two bottles of wine we got on the ship. Went to customs. They looked at us, asked how many, looked at each other and said Merry christmas and let us go. We filled out our paper work, were honest about what we had, pulled out the cash and we were flaged on. Get the booze, They are most in 1Lt. bottles and the cost is less than US, even if you have to pay a few dollars for then. We always take bubble wrap and pack in our checked bags. In 2007, we took 7 bottles and no one said a word. They never opened our bags. As far as buying at a port, we took a bottle on in a back-pack and they never took from us.