Hi
I am from the US, ex mariner, ex licensed captain. Currently in Ecuador. I ve also lived a bit in Central and South America...... so here is a suggestion, may work or not....
Why not go directly to the Guarda Costa or the Nicaraguan Coast Guard or the part of the navy responsible for whatever section of the coast you are interested in. Dont e mail them, go directly to whichever district office is responsible for your area of interest , sit down and have a talk with them to see what you can find out. My first guess is that you will have better luck with the people responsible for enforcement of maritime safety than you will with functionaries pushing paper in a city several hundred kilometers distant. I know this worked for me in Mexico and more than once in the US. My experience is most officials will be happy to talk to a foreigner-- plus the initial contact is a valuable contact in building a good relationship. This can be very helpful in the future of your venture.
Just a thought. Good luck, fair winds and following seas
Expat