Deep Sea Fishing?

I will be going here for my first time in October and am really looking forward to it. I would like to surprize my boyfriend with a deep sea fishing trip while we are in port. Are there trips that we can buy directly off the ship (not an excursion through Carnival)? Are the prices negotiable/reasonable? Any recommendations? Thanks!

http://oceanencounters.com/en/diving-a-snorkeling/fishing-trips

if you have never looked into a private deep sea trip ... they are very $$$

In Port Canaveral a half day trip can run $500 or more (plus tips)