Since our property backs up to the Lagoon, we take water safety very seriously. We recommend you keep the dock gate closed at all times -- especially if you have young children. We recommend you not allow children in the backyard and especially on the dock without an adult present, and that the adult can swim.
Yes you can kayak / SUP in the lagoon, BUT with some very important caveats:
You do so at your own risk. Water sports are dangerous and you expressly agree to shoulder all liability for any such activities. We have life jackets in a a storage locker on the dock, but recommend you bring your own to ensure proper sizing.
And: The part of the lagoon behind our house is "fast water" which means speedboats go back & forth. Don't go out into the middle of the lagoon here -- you may get hit by a speedboat!
San Mateo lagoon regulations mandate you must stay within 10 feet of shore to travel from here to the "slow water" areas where you can relax and enjoy the lagoon and beach.