- Chances
- Dangers
- Hazards
- Jeopardises
- Coral banks
- Coral formations
- Coral hazards
- Coral structures
- Gold-bearing veins for Coral Banks
- Lodes
- Masses of rock
- Frozen floating masses
- Shipping hazards
- Frozen floating masses
- Frozen masses
- Frozen shipping hazards
- Large, floating masses of ice
- Lettuces found at the poles
- Polar shipping hazards
- Shipping hazards