Mooring buoys: buoys that support the cables or chains to which vessels are attached may be made in which shapes for practical identification and performance?

Introduction / Context:
Mooring buoys provide fixed attachment points for vessels using chains or synthetic lines. Their external shapes assist with visibility, stability, and handling in the local sea state, and conventions vary by authority and purpose.

Given Data / Assumptions:

• Buoys may be cylindrical, drum-like, pear-shaped, or spherical.
• Function: support mooring chain/cable and indicate the mooring position.
• Design must account for buoyancy, stability, and snag-free hardware.

Concept / Approach:
Different shapes balance stability and visibility: spherical for all-direction visibility, pear for better stability in waves, cylindrical/drum for manufacturing simplicity and deck handling. All serve the core function of supporting mooring cables.

Step-by-Step Solution:
Relate each offered shape to practical use: all are found in service as mooring buoys.Hence, the inclusive option is correct.

Verification / Alternative check:
Harbour authority catalogs list these shapes under mooring buoy types.

Why Other Options Are Wrong:

• Picking a single shape ignores the variety used internationally for the same function.

Common Pitfalls:

• Confusing lateral navigation buoys with mooring buoys; the latter are for tying up, not channel marking.

Final Answer:
all of these.