All together 39 Iris-class bouy tenders were built for the United States Coast Guard. Many of these ships were in service for more than 50 years. The USCGC Bittersweet (WLB 389) was laid down on 16 September 1943, launched in 11 November 1943 and commissioned on 11 May 1944. The ship was built in Minnesota by the Zenith Dredge Company of Duluth. During WW II the vessel was mainly stationed in Alaska (homeport Kodiak). Her primary duty was to service the navigational aids, but she also saw service in various search and rescue operations. She could also be used as an icebreaker. Many estonian sailors who were stationed on soviet fishing ships remembered Bittersweet while sailing near the George Brown fishing territory in Alaska. Kodiak remained the ships homeport until 1964, from 1964-1976 USCGC Bittersweet was stationed in Ketchikan and later on Woods Hole, Massachusetts. The ship was fully renovated in 1976-1978 and again in 1991.
It is worthy of mentioning that in 1990 the ship aided the passanger ship Regent Star. The aforementioned ship struck the lowlands and because of that Bittersweet rescued some 882 people. On the same year Bittersweet also assisted the rescue of 682 people from the passanger ship Bermuda Star.
In the early 1990`s Estonia was forming her own maritime fleet and worked hard towards joining the NATO. In 1994 when Estonian Border Guard director captain (navy) Tarmo Kõuts visited the United States where he learned that the United States Coast Guard was about to decommission some ships. Kõuts thought that maybe some of these ships could be used in Estonian Border Guard duties. An agreement was made that Estonia might get some vessels from the USA in the following years. In 1997 the Estonian crew of 20 men were sent to Boston where they recieved necessary training for operating the vessel. The ship was renamed Valvas and the Estonian flag was hoisted on 5 September 1997. The commanding officer was captain Knut Mitt. On the following day Valvas started her journey across the Atlantic ocean and reached Tallinn on 27 September. The voyage was plagued with a stormy sea where waves reached up to 24 m/s. But the ship held her own and the crew navigated her safely to Estonian port. It is worthy of mentioning that after regaining independence Valvas was the first ship that crossed the Atlantic ocean under the Estonian flag.
During her first years of servcice in the Estonian Border Guard the ship was stationed in Pernau harbour where she worked as an icebreaker. She was also used in many search and rescue operations and was the command and support vessel of naval exercises in Estonian waters. In April-May 2000 Valvas took part of the international exercise SAREX 2000 near Bornholm, in June 2000 participated in Estonian-Finnish sea rescue exercise „Keri 2000“, in August-November 2000 was the command and support vessel for BALTRON (Baltic Naval Squadron). In 2002 took part in Estonian-Finnish-Russian sea rescue joint exercise „Puhas meri 2002“. The ship also took part in land and sea military training cooperation, such as in the „Erna Raid 2003“ where a troop landing operation in Kolga bay was launched from Valvas. The ship saw further service as a support vessel in international naval exercises of „Open Spirit 2003“.
Valvas took part in many search and rescue operations in Estonian waters. For instance in 2006 she was the command vessel for the sea rescue operation near the island of Vanidloo where a merchant ship Runner 4 sunk. Valvas was withrawn from active service in 2010. In 11 July 2014 the ship was handed over to the Estonian Maritime Museum and is located in the Lennusadam harbor (Tallinn).
General characteristics of PVL-109 Valvas while commissioned in the Estonian Border Guard:
|Type||Patrol/command and support vessel|
|Propulsion (main engines)||2 x General Motors EMD (Electro Motive Division) diesel engines, 1500 hp|
|Auxiliary engines||2 x Detroit Diesel, 630 hp|
|Main generator||2 x DC Westinhouse GE 490 kW|
|Drive shaft motor||Westinghouse DC 1200 hp|
|Range||4500 miles (max speed) / 13 500 miles (economical)|
|Fuel tanks||92 t|
|Complement||15-30 (originally 20 in 1997)|
|Armament||2M3 (1 x 2-25 mm)|
|Rescue equipment|| Zodiac inflatable boat (for 13 people), TANDAB inflatable boat (for 10 people)
4 liferafts (for 15 people each), 6 life rings, 65 rescue suits
|Cargo boom||20 t|
|Hoisting crane||2,6 t|