The water temp is around 18 to 23 Celsius, but the Humboldt current can bring cooler water. Depends what you're used to, but a spring suit sounds right.
Here are some other tips for you from WorldNomads.com.
Phil from the safety hub. almost 6 years ago
From June to December the southern trade winds bring the colder Humboldt Current north to the Galapagos. This means that the water is cooler, and a layer of high atmosphere mist pervades the island skies.
In effect, the highlands of the larger islands are kept green and lush while the sea level islands and shorelines have little precipitation. Thus, June to December is generally called the "dry season" which is known for its blue skies and mid-day showers.
During this season the tourists may observe a large number of species around the islands and in the sea such as giant tortoises, humpback whales, blue-footed boobies, cormorants, oyster catchers, lava lizards, Galapagos hawks, masked boobies, swallow-tailed gulls, sea lions, lava herons, brown noddies, and penguins. Due to the water temperature, it is the perfect time for diving.
So I think you choose best time for visit Galapagos Island and yes where your question based on snoring then yes you must ensure all things before snoring. You may take help from travel agency as ecuadorgreentravel for your best trip. about 3 years ago
It depends where you snorkel - a sheltered beach area or the port on Isabela (where the sea lions play with you) is much warmer than a rocky shore open to the currents. If you take a cruise, most boats will provide you with a wetsuit free of charge. Lots of places in the towns will rent a wetsuit to you. about 3 years ago