Buoy Field Alignment
Lake Tahoe is a large freshwater lake in the Sierra Nevada of the United States. At a surface elevation of 6,225 ft (1,897 m), it straddles the border between California and Nevada, west of Carson City. Lake Tahoe is the largest alpine lake in North America. Its depth is 1,645 ft (501 m), making it the second deepest in the United States after Crater Lake (1,945 ft (593 m)). Additionally, Lake Tahoe is the sixth largest lake by volume in the United States at 122,160,280 acre·ft (150,682,490 dam3), behind the five Great Lakes.
The lake was formed about 2 million years ago and is a part of the Lake Tahoe Basin with the modern lake being shaped during the ice ages. It is known for the clarity of its water and the panorama of surrounding mountains on all sides. The area surrounding the lake is also referred to as Lake Tahoe, or simply Tahoe. More than 75% of the lake’s watershed is national forest land, comprising the Lake Tahoe Basin Management Unit of the United States Forest Service.
Lake Tahoe is a major tourist attraction in both Nevada and California. It is home to a number of ski resorts, summer outdoor recreation, and tourist attractions. Snow and skiing are a significant part of the area’s economy and reputation. Mountain and lake scenery are attractions throughout the year. The Nevada side also includes large casinos. Highways provide year-round access to the area.
Lake Tahoe is the second deepest lake in the U.S., with a maximum depth of 1,645 feet (501 m), trailing only Oregon’s Crater Lake at 1,949 ft (594 m). Tahoe is also the 16th deepest lake in the world, and the fifth deepest in average depth. It is about 22 mi (35 km) long and 12 mi (19 km) wide and has 72 mi (116 km) of shoreline and a surface area of 191 square miles (490 km2). Approximately two-thirds of the shoreline is in California.
The south shore is dominated by the lake’s largest city, South Lake Tahoe, California, which adjoins the town of Stateline, Nevada, while Tahoe City, California, is located on the lake’s northwest shore. Although highways run within sight of the lake shore for much of Tahoe’s perimeter, many important parts of the shoreline lie within state parks or are protected by the United States Forest Service. The Lake Tahoe Watershed (USGS Huc 18100200) of 505 sq mi (1,310 km2) includes the land area that drains to the lake and the Lake Tahoe drainage divide traverses the same general area as the Tahoe Rim Trail.
Lake Tahoe is fed by 63 tributaries, which drain an area about the same size as the lake; half the water entering the lake is rain or snow falling directly on it.
The Truckee River is the lake’s only outlet. The Truckee flows northeast through Reno, Nevada, and into Pyramid Lake, Nevada, which has no outlet. Only one third of the water that leaves the lake leaves via the Truckee, however; the rest evaporates from the lake’s vast surface. The flow of the Truckee River and the height of the lake are controlled by a dam at the outlet. The natural rim, at which the lake can be allowed to flow out through the dam, is at an elevation of 6,223 ft (1,897 m) above sea level. The maximum legal limit, to which the lake can be allowed to rise in order to store water, is at an altitude of 6,229.1 ft (1,898.6 m) above sea level.
The Annapolis Harbor has both public rental and private annual mooring buoys available. The 76 public rental moorings are located in Spa and Back Creeks in five separate mooring fields that vary in maximum allowable vessel LOA, and pricing. Public moorings are rented on a first-come-first-served basis with the exception of City-sponsored special events. Private annual mooring buoys are located in Weems, Spa, and Back Creeks, as well as the Severn River. They are to be utilized only by vessels for which valid Annual Mooring Permits have been issued.
Annapolis mooring fields
Main Field – The largest and most popular mooring field is in Spa Creek between the Spa Creek Bridge and the Naval Academy. This field is also known as the “Front Forty,” in reference to the 40 mooring balls, numbered 1 through 40. These moorings are available for $35 per night. Be advised that there are two tiers of mooring balls within this field, according to the maximum allowable vessel LOA, and therefore differ in appearance.
The field contains 28 standard, white moorings which can hold vessels up to 45 feet LOA.
There are 12 moorings that display a yellow cover; these moorings can hold vessels up to 55 feet LOA.
Saint Mary’s Cove – Just past the Spa Creek Draw Bridge, headed westbound on your starboard side, is the Saint Mary’s field that contains 20 moorings numbered 41 through 60. These moorings can accommodate vessels up to 35 feet LOA and cost $25 a night.
Well’s Cove – Continuing further west up Spa Creek past the #3 day marker, on your port side, is Well’s Cove that contains 6 moorings numbered 61 through 66. These moorings can hold boats up to 45 feet and cost $30 a night.
Truxtun Park – Further up past Well’s Cove, also on your port side, is the final mooring field located in Spa Creek. It is located off the banks of Truxtun Park. This field contains 5 moorings numbered 67 through 71. Again, these moorings can also hold boats up to 45 feet and cost $30 per night.
Back Creek – There is one field located between Bert Jabin’s Yacht Yard and Port Annapolis in Back Creek. This mooring field contains 5 moorings numbered 72 through 76. Once again these moorings can hold vessels up to 45 feet and cost $30 per night.
Weekly rates are available for all public mooring fields. The weekly rate consists of payment for six days at the daily rate for that field, and then the seventh day is included at no charge. Be advised that previous mooring purchases cannot be retroactively applied towards a weekly rate after the fact. We can only offer weekly rates moving forward from the date of purchase.
Rules and Buoy Field Mooring Method in the area
For your protection and the protection of other boats moored in the buoy field, please comply with the following standards:
- Nylon tether lines must be a minimum of 1/2” in diameter and between 6 and 8 feet long. These lines should be secured to the top ring of the buoy.
- Depending on the height of your bow above the water, keep the mooring lines short enough and attach a float so they do not wrap under the buoy.
- Connect each of your lines separately to the top of the swivel, so that if one line fails, the other will serve as a backup.
- Use properly installed thimbles (galvanized) and shackles on each line to avoid excessive wear at the point of connection.
- Use stainless steel wire or plastic wire ties to secure the shackle pins so the shackles will not loosen.
Underwater Hazards In some areas close to shore there are many underwater obstructions, such as rocks and old pilings, which may be exposed or barely covered when the lake level drops in summer. Most dangerous shoreline areas have been marked by the U.S. Coast Guard with red or diamond buoys, which should be kept between the vessel and the shore. These dangerous areas and buoys are shown on the National Ocean Service Chart #18665 of Lake Tahoe. During heavy wind and wave conditions, buoys can be dragged off their charted positions. Extreme caution should be used around all shore areas. Water beyond the buoys is free from underwater obstructions, but generally too deep for anchoring.
There are numerous mooring buoys and mooring buoy fields around Lake Tahoe. Use caution and slow speeds when transiting around these mooring areas. DO NOT USE MOORING BUOYS FOR NAVIGATION. If you own a mooring buoy, you need a permit from the Tahoe Regional Planning Agency, (775) 588-4547 x 301, the U.S. Army Corps of Engineers, and the appropriate State Lands agency (California or Nevada) to legally use moorings on Lake Tahoe. Additionally, TRPA has instituted a buoy identification program. All permitted buoys must display a TPRA buoy identification tag AT ALL TIMES.
If your boat is anchored at night or tied to a mooring buoy at night, it must be equipped with an all-round white light, exhibited where it can best be seen, and visible for two miles. The light must remain lit the entire night during mooring.
Finally, remember that the other end of the lines where they connect to your boat are just as important. Protect the lines from chafing and make sure the fittings on your boat are properly secured and adequate to hold your boat in a storm.
There are several locations in Indianapolis that stock properly assembled mooring lines.
No boat should be improperly secured in the buoy field for lack of a proper rig. If you need assistance, please request help from the facility manager.
Another method is been currently developed through the use of the inertial navigation technique. Strapdown inertial navigation system (SINS) is presently used in several applications related to aerospace system and marine navigation. The accurate initial attitude is essential to ensure the precise determination of the position and attitude of the moving platform, which is usually calculated using initial alignment. When the vehicle is moored, the SINS inevitably experience disturbing motion. The method of ground coarse alignment, which is based on the assumption that SINS is on a stationary carrier with limited vibration, therefore cannot be used to perform the SINS mooring alignment. In this paper, a novel method processing the gyro and accelerometer measurements with infinite impulse response (IIR) digital low-pass filter to remove the high frequency noise is investigated for marine mooring alignment. Its algorithmic principle is described in details. The results obtained from both simulation and mooring experiment show that the attitude determined by this novel method can meet the accurate alignment.