Wave-Related Factors

MIL-HDBK-1025/5

Floating slips with tapering or round bottoms shall be

e)

provided so that the pinching effect of the ice squeezes them upward.

To prevent erosion of basin perimeters and revetted slopes by

f)

expanding ice sheets, the perimeter slopes shall be provided with smooth

concrete lining. Vertical perimeter walls may be pushed back into soil behind

them in winter and sprung back when the ice thaws.

Deflecting booms made of logs or heavy timbers shall be used

g)

to protect the berthing area from drifting ice.

Fog. For areas where fog is a significant problem, small craft

2.2.1.4

harbor entrance channels and main fairways should be designed as straight as

feasible, so as to be safely navigable in dense fog by following marker buoys

and other channel-marking devices with as few turns as possible.

Wave-Related Factors

2.2.2

Swell

2.2.2.1

To reduce wave action from the entrance channel and interior

a)

basins to acceptable heights, the entrance channel orientation protective

breakwaters and jetties, and interior wave-dissipating devices, shall be

properly planned and selected.

Historical wave data and statistical hindcast data shall be

b)

used for orienting the entrance and designing protective structures.

Wave-dissipation structures shall be provided to reduce waves

c)

to acceptable heights. Criteria for acceptable maximum wave heights are about

2 to 4 feet in the entrance channel, and 1 to 1 l/2 feet in the berthing areas

depending on the characteristic of the using craft.

Where a small craft harbor opens into the ocean or a large

d)

lake, the entrance shall be oriented for a boat to enter without turning

broadside to the incoming waves.

Surge

2.2.2.2

Surge oscillations in the basin cause stress in mooring lines

a)

and anchorage systems, and can make boat maneuvering into slip difficult.

Vertical basin walls are usually more desirable than poorly

b)

reflective basin perimeters, and rectangular basins are more efficient than

irregular shaped basins for berthing arrangements.

Most recreational boats in a small craft harbor are

c)

insensitive to long-period surging. Larger craft may experience fender and

mooring line difficulties under long-period surging.

Tides

2.2.2.3

Ocean tides may extend considerable length upstream from the

a)

mouth of large rivers and are semi-predictable for most harbor sites. For any

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