I would love to have a boat, but then with a captain and with someone who maintains it, moors it, and ties nautical knots. Just let me make delicious snacks, and take care of sunscreen and drinks.

So the best thing is to make friends with people who have a sloop. Good idea to work on that this summer. Amsterdam from the water is breathtakingly beautiful, and if the sun is shining, I am a happy person. If you don't have acquaintances with a boat, you can also just rent one. You do need to be able to sail a bit, of course.

On bootjehureninamsterdam.com you can rent a boat for six people for around 100 euros. They are whisper boats and those are my favorite. You can all understand each other and there's no annoyance from the constant thumping of the engine. They run on electricity, so that's also good for the environment. You obviously have to adhere to the sailing rules, but for such a whisper boat, you don't need a sailing license, as they are easy to steer.
Just make sure to honk well before you go around a corner. Tour boats hate small boats, so don't assume they will just move aside for you.

I find it the most fun to take a basket full of the tastiest things. Snacks that you can easily eat, such as: sandwiches, chicken legs, savory pancakes, frittata, meatballs, crudités with dip. For drinks, I prefer to bring homemade ginger lemonade and cold bottles of wine. But you can also choose to moor somewhere to have lunch. Then the captain can also just eat calmly. I'll give you some nice addresses where you can easily arrive by boat.

Café George on the Leidsegracht. There is a small mooring spot, so you have to be lucky. The boat often lies nicely in the shade. If you want to have lunch there, it's wise to make a reservation.

Hannekes boom. A large terrace, next to the Central Station at the IJ, has a lot of picnic tables. There is a very chill atmosphere and the menu is full of snacks.

Hotel L’europe and Amstel hotel are very fancy hotels and you definitely need to bring your wallet there, but well, if you really have something to celebrate, it is very festive.

Near the Amstel hotel is Café de Jaren. Large terrace and you can safely leave your boat there for a while.

Amstelhaven has enough space to moor and there is a huge deck terrace where you can comfortably stay all day until the sun goes down.