With a Gemini
in the USA, it's a non-issue.
We just sold ours (bought a boat in Europe) but we have done the Great Loop 1.5 times around with a great many marina stays over 10years.
At 14' beam, it's very rare we couldn't fit in a standard slip. Only a couple of times was it even suggested there might be an upcharge for being a catamaran
but they always backed off when they realized our beam (got in the habit of asking for a slip for a 34'X14' sail boat with a 3' draft
and most never realized we were a cat until we showed up and it was going to be hard to explain why the price
Sometimes we wound up on an T-head but never out of necessity due to the beam.
At 16', the Tomcat isn't going to be a huge issue but you may get forced onto the T-head occasionally as a lot of 35-40' slips are 16' across, so there is no margin for error if the boat has a 16' beam.