Well if it *has* to be a portable then get this:
https://www.amazon.com/Tecsun-PL880-Con ... 00GJ51NVA/(For a portable it is almost good enough to be a desktop replacement. Yes, it's really that good.)
You definitely will need SSB for anything useful these days except broadcast. Don't get any portable with a "BFO" -- make sure it has dedicated USB/LSB modes.
No, ships don't use CW any more -- it's almost all satellite-based. Technically they have that capability but as emergency backup only.
HAMs send 'messages' in voice (SSB), CW (morse code) and DATA. Data refers to many, many different modes. I won't bore you with the details. If you're curious then you should pick up the ARRL handbook:
https://www.amazon.com/ARRL-Handbook-Ra ... 1625951078 (You should be able to find the above handbook in a local library. It may not be the 2020 version but it's worth checking out.)
HF-SWL can be fun but it takes a lot of patience and persistence to catch the 'interesting' stuff. And with all of our electronic toys these days, there's a lot of interference around neighborhoods to choke a chicken. (And it ruins the fun of HF to say the least.) Also a lot of users have cut back using HF radio for satellite -- such as USCG. US Military still has limited HF use and part of the fun is just trying to hunt them down.
FWIW, don't bother with HF using a cheap USB dongle. You'll be very disappointed. A SDR made for HF frequencies is a must. Check out the RSPdx or Airspy HF+ (which uses SDR#)
Of course, a decent antenna is a must. You can make a simple wire antenna for a few $$ or invest in a magnetic loop antenna -- which is to say it's amplified. They are really good for HF. If you have a lot of RFI (interference) then no antenna will help.
Good luck.