August is the month when ocean swimming is at its best and with the recent heat wave, this year that is more true than ever. Thousands of Islanders and vacationers of every description can be found at the shore at all hours, savoring the waning summer days and sunsets over the ocean.

But as signs now posted at Long Point Wildlife Refuge and other south-facing beach areas remind us, this is also the month for dangerous riptides. Sometimes hurricanes and tropical storms can come barreling up the coast from waters south of the Vineyard — and even when the storms stay well offshore they can kick up dangerous surf and rip currents.

Riptides are narrow, fast-moving ribbons of water that are capable of carrying swimmers who are unaware of the conditions far out to sea. On the Vineyard riptides are most likely to appear along the south shore, from South Beach in Edgartown to the far more remote beaches up-Island. Riptides are fickle and unpredictable and can change rapidly depending on the tides, currents and wind, but they are at their most dangerous when the tide is high and conditions are rough. Surfers and strong, adventuresome swimmers love these conditions, but lifeguards and emergency responders who work on Island beaches in the summer months know well how treacherous they can be.

A few tips for swimmers who become caught in a rip current: The instinct is to swim out of the current, but that is the wrong thing to do. Do not try to fight the current or swim against it, instead ride the current out by swimming parallel to shore until the rip subsides and you can safely make it in. If you are too tired to swim, float or tread water. Most riptides are not more than 30 feet wide, and you will soon be out of danger.

Swimmers are encouraged to be vigilant at all times and practice good water safety habits. Never swim alone. Try to choose beaches where there are lifeguards on duty, especially if you have small children.

Finally, swim smart. If conditions are rough, do not go in the water. The ocean will always be there for another day.