I live in Calgary, Alberta. Planning a beach day can be a big deal because many would say that the nearest "real" beach is at Sylvan Lake, 90 minutes away. But that wasn't always the case. When my kids were little, we lived in Vernon, BC where we had a choice of three beaches that were accessible with a ten minute drive. Finding something to do on a hot day, like going to the beach, was a quick and fairly easy option even if it was only for an hour.
One can still find places in Calgary where the kids can splash in the water: Sikome Lake, St. Patrick's Island Park, Bowness or Edworthy Park, and various splash pads throughout the city... but I digress. This isn't so much about where to go, but rather how to set yourself up in a way where it becomes easy instead of requiring 24 hours of planning. Even a spontaneous trip to Sylvan Lake isn't quite so daunting when much of the preparatory planning is taken care of.
Tip #1 - Have a Grab Bag
Create a beach bag and that is ready to go! Keep it stocked with things you will need, but keep it minimal. We don't have to make a formal day trip out of this requiring multiple camp chairs, 10x10 sunshade, lounging cots, tubs full of sand toys, large floaties etc. I'm picturing essentials like: sunscreen, hats, napkins, disposable forks (or cheap $ store ones) and water wings. Even if it means I have to buy an extra tube of sunscreen or a package of baby wipes to specifically keep in this bag, it means that I don't have to run all over the house looking for them.
Tip #2 - Be prepared - at least a little bit
Our family always has half-filled water bottles in the freezer. Not only are these good for any daily occasion, but they will double as ice packs to keep any food and other items cool (for at least a good part of the day).
Tip #3 - Make food easy
Have a list somewhere - whether that's in the bag or on your phone - of foods that your family likes to eat at the beach. If you are planning for a longer day, a picnic might be called for; if it's just a couple of hours, you might only require snacks. If you don't have things prepared the night before remember that it's easy to stop at a grocery store as you head out. When it comes down to it, know what things are quick and easy.
Tip #4 - Make kids independant
Don't take on the responsibility of rounding up all this stuff yourself. Ensure that kids know where their own swimsuits are kept and which towels are suitable for day trips. You don't want your super-fancy, super-plush, super-expensive towels full of sand, so permanantly assign certain ones to each child (does anyone else "colour-brand" their children?) Keep 1-2 extra, not 12 extra, in the linen closet just in case. Let them put together (and carry!) their own bag of beach items - you may wish to quickly inspect them before you leave the house. Even littles can carry their backpacks from the car if you have them packed up. Bonus tip? Your cooler bag will be a lot lighter if you stick everyone's water bottle in their own bag.
Tip #5 - Take advantage of less busy times
Create a plan to arrive and take off before the beach gets too busy and everyone is hot and tired. After a full day of sun and play most families won't need a big dinner when you get home, so give yourself a break by keeping it simple.
Tip #6 - Other quick beach hacks
One of my favourite recent hacks is using a large fitted sheet and tucking our stuff into the corners rather than laying out our towels directly on the sand. My second fave tip is bringing along some plastic grocery bags for wet bathing suits and/or easy trash disposal at the end of the day.