It was thirty degrees out and the wind blew a fine, chlorinated mist across the water, but there was swimming under the stars in Cambridge Wednesday night.

The Holiday Inn of Cambridge--formerly the Cambridge House Moter Hotel--opened the first year-round outdoor swimming pool in the area. It has also redecorated its St. Clair's Regimental Room in a Yard of Ale vein, and renamed it Captain of the Guard (Rum and Rations).

The water will be kept at a constant heat of 85 degrees, but it was cooler Wednesday night, and 15 models, though garbed in this year's comparatively covered suits, did not stay in very long.

Although the pool will be available only to patrons, passers-by on Mass. Ave. can view the summery scene through its one transparent wall. There is no roof, but the management promises that heat from surrounding infrared lamps will fight the chill.