Bremen and Niedersachsen in Germany may not be the first places that come to mind when you think of scuba diving, but there are some interesting dive sites in this region for all levels of experience.

Best Scuba Diving Spots for Experienced Divers:
The region offers some good wreck diving opportunities such as the "Leu", a 120m-long wreck, and "Helmut", a minesweeper that sank in 1945. These wrecks are suitable for experienced divers as they can be quite deep and challenging, with limited visibility. Other interesting spots include the "Wrecker's Yard" in the Weser river, which is home to several wrecks, and the "Steingrund" reef, which is a popular spot for underwater photography.

Best Scuba Diving Spots for Beginners:
For those who are new to scuba diving, there are several shallow dive sites in the area that offer calm conditions and good visibility, such as the "Seebad Eckernförde", a shallow reef with lots of marine life, and the "Herkulesbrücke", which is an interesting dive site with lots of fish and a maximum depth of 12 meters.

Marine Life:
The marine life in Bremen and Niedersachsen is diverse and includes a range of fish such as cod, flatfish, and herring, as well as crabs, lobsters, and even seals. In addition, divers can also spot some interesting wrecks and artifacts from World War II.

Dive Conditions:
The visibility in this region can vary depending on the dive site and the weather conditions, but can reach up to 20 meters in some areas. Water temperatures can also vary, with temperatures ranging from 7°C in winter to 20°C in summer.

Cost:
The cost of scuba diving in Bremen and Niedersachsen can vary depending on the dive center and the type of dive, but generally ranges from 30-50 Euros per dive for certified divers, with discounts available for multiple dives or dive packages. Diving courses are also available for those who are new to scuba diving, with prices starting from around 300 Euros for a basic open water certification course.