I carry a spare belt as well along with the needed tools to replace in the water. One of those tools are bung plugs to fit into the raw water pump hoses that need to come off to put on a new belt. The intake hose is below the water line and thus will flood the boat if not plugged up.
I have read in other places that some will tie up the belt using zip ties already behind the hoses so no reason to remove any hoses.
Everything looks good and clean in your pics and no ‘belt dust’ so no rust on the pulleys and everything is aligned. However, given the age, best to check out the idler and tensioner pulleys to ensure still ok.
Here is a
link to get the needed diagrams and part nos for the hoses. Don’t’ overlook the ones to the fuel pump and do not be surprised at the high cost of some of these. And here is a handy tool set to help remove hoses
link. You will not be sorry to have it.