Also, I know from a PM you sent me that your
boat draws 6'2". If you go the inside
route in Belize then you will have plenty of
water N bound in the Inner Channel as far as Belize City. N of there you will spend a lot of time very close to the bottom...especially as you
head N from about Caye Cauker to Ambergris Caye. Alternatively, you could clear out in Belize City and exit Eastern Channel with lots of
water under your
keel.
The easiest way to clear out near Belize City is to go into Cucumber Beach Marina and have them call officials for you, but the entrance channel tends to silt up with a controlling
depth of about 6' or less depending upon status of dredging. Alternatively you can
anchor off in Sibun Bight and
dinghy into the marina.
Good deep
draft anchorages N bound about a day run apart include New Haven Bay, Placencia Harbor, and Sibun Bight. If you clear out of
Guatemala the day before departure then get an early start you can make New Haven Bay. Next early AM while you've still got a favorable but light land breeze make for Placencia. Then onto Sibun Bight or Cucumber Beach Marina if you want to try and make it in. There are a number of other feasible options for your
draft, but these are the ones I usually use when running
boats back and forth from the Rio.
You asked about
marinas on another thread. Very limited options for your draft in Belize. You could make it into Roberts Grove Marina in the back
lagoon in Placencia, but I would hire local knowledge for that. Ditto for Chabli Mar or Laura Beya also on the back
lagoon. Probably not worthwhile unless you plan to stay in them for a while. And, the anchorage is good so really no big motivation unless you need
shore power or want to leave the boat. There is a big marina
project on the coast just N of Placencia that looks like it could easily accommodate you, but I've never used it and don't know the status.
You can clear in/out at Big Creek just across from Placencia.
Offshore route, since you've mentioned you want frequent breaks, you could stop in at the Sapodilla Cayes near the S end of the Belizean barrier reef and then at the atolls. Technically you should be cleared in to do this, but officials are sparse in these locations so you are not likely to have any issues.
I don't know the Mexican coast well, but others can chime in there.