The Wailuku beaches are not the best beaches on the island of Maui. They can be good for surfers and beach walks but are not the best places to go to if you are wanting to swim or sunbathe due to the consistently windy conditions. In addition to the wind, the currents also come directly onshore to the beaches of Wailuku. This brings in a tremendous amount of ocean debris which can be a blessing and a curse. If you are looking for some glass fishing floats or other collectible items.
The closest thing you can get to a nice beach near Wailuku is Kanaha Beach which is actually over in Kahului near the airport. The winds make it less than ideal for most activities, but they actually make for PERFECT kitesurfing conditions. If you are in the area and have never seen kitesurfers in action before you should stop by and take a peek at what they can do. If you are staying in Wailuku and wondering what kind of options of Wailuku beaches there are you should probably look into taking a trip to another part of the island that has more to offer.