Not sure where to post?
I know I’m a boat u can use the vhf channels etc 19, 9. If u are fishing on the beach but in the water can I legally use it? For emergencies?
You would not be covered by the Part 80 rules for this sort of application.
Calling for help from the USCG would result in them responding with an expensive and noisy helicopter or boat. They will not be amused to find you sitting on the beach with a radio. They'll help you, then you'll get a talkin' to.
If you are on land, even wading in the surf, the local agencies will be able to respond much faster. Use a cell phone as that will get you to the local 911 answering point, and they'll see your location and know exactly who to send (might even be the USCG, but let the professionals decide that…)
If you are out of range of cellular service, and do that sort of stuff regularly, and expect to be in an emergency situation (you should always assume that you will be), then get one of the following:
A cell phone that will do SMS via satellite. Some of the newer iPhones and I think Samsungs will do that.
Get a Garmin InReach or similar device.
Unless you specifically have a human on the other end of the radio that is expecting you to call for help in an emergency, don't expect to get help via ham radio, GMRS, CB, FRS or anything else. Use the correct tool for the job.