commercial purposes will be entitled to lockage only at the end of each hour, but whenever a lockage is made for a commercial boat other craft may likewise pass through if there is room for them in the lock. Lock masters shall have final decision as to whether a craft presenting itself for lockage is commercial or a pleasure boat.

(d) Order of lockage.-Boats having any other craft in tow must accompany their tow through the lock whenever so directed by the lock master. Lock masters may require tows requiring two or more lockages to permit other craft to pass after each lockage.

(e) Signals. Signals from vessels shall ordinarily be by whistle. Signals from locks to vessels shall be by whistle, or other sound device or by semaphore, or visual means. When whistle is used, long blasts of the whistle shall not exceed 10 seconds and short blasts of the whistle shall not exceed 3 seconds. Where a lock is not provided with a sound or a visual signal installation, the lock master will indicate by voice or by the wave of a hand or lantern when the vessel may enter or leave the lock.

Vessels must approach the locks with caution and shall not enter nor leave the lock until signaled to do so by the lock master. The following lockage signals are prescribed:

(1) Sound signals by means of a whistle. These signals apply at either a single lock or twin locks.

(1) Vessels desiring lockage shall, on approaching a lock give the following signals at a distance of not more than 1 mile from the lock: If a single lockage only is required: One long blast of the whistle followed by one short blast.

If a double lockage is required: One long blast of the whistle followed by two short blasts.

(11) When the lock is ready for entrance, the lock will give the following signals:

One long blast of the whistle indicates permission to enter the lock chamber in the case of a single lock or to enter the landward chamber in the case of twin locks.

Two long blasts of the whistle indicates permission to enter the riverward chamber in the case of twin locks.

(III) Permission to leave the locks will be indicated by the following signals given by the lock:

One short blast of the whistle indicates permission to leave the lock chamber in the case of a single lock or to leave the landward chamber in the case of twin locks.

Two short blasts of the whistle indicates permission to leave the riverward chamber in the case of twin locks.

(IV) Four or more short blasts of the lock whistle delivered in rapid succession will be used as a means of attracting attention, to indicate caution, and to signal danger. This signal will be used to attract the attention of the captain and crews of vessels using or approaching the lock or navigating in its vicinity and to indicate that something unusual involving danger or requiring special caution is happening or is about to take place. When this signal is given by the lock, the captains and crews of vessels in the vicinity shall immediately become on the alert to determine the reason for the signal and shall take the

(2) Visual signals. At locks where density of traffic or other local conditions make it appear necessary or advisable, the sound signals given by the lock will be supplemented by the following visual system:

At single locks, a green flashing light will be displayed on the land wall opposite the upper gate, at least 15 feet above the land wall, showing upstream through an angle of 120°; and the same type of light will be displayed opposite the lower gate at least 15 feet above the land wall, showing downstream through an angle of 120°, indicating that the lock gates are open and that the lock is ready for entrance. At double locks similar green flashing lights will be displayed on the land wall opposite the landward lock gates. In addition, amber lights will be displayed on the intermediate wall opposite both the upper and lower gates of the auxiliary lock, indicating that the auxiliary lock gates are open and ready for entrance.

These flashing lights will operate only when the respective gates are seated in the recesses, contact being made automatically by the gates when fully open.

In all cases, however, vessels will use the whistle signals prescribed in (1) above to signal for a lockage.

(f) Stations while awaiting lockage.-Descending boats while awaiting their turn to enter a lock shall lie at least 400 feet above the lock and shall leave sufficient room for the passage of boats leaving the lock or those having precedence in entering. Ascending boats while waiting their turn to enter shall either tie up sufficiently far below the lock or keep out far enough to give free passage to a boat entering or leaving the lock.

(g) Rafts.-Rafts to be locked through shall be moored in such manner as not to obstruct the entrance of the lock, and the sections for locking shall be brought to the lock as directed by the lock master in charge. After passing the lock the sections shall be reassembled at such distance beyond the lock as not to interfere with boats privileged to pass through.

(h) Entrance to and exit from locks. In case two or more boats or tows are to enter for the same lockage, their order of entry shall be determined by the lock master. Except as directed by the lock master, no boat shall pass another in the lock. The boat that enters first shall have precedence in exit.

(i) Protection of lock gates. In no case will boats be permitted to enter or leave the locks until directed to do so by the lock master. Boats shall not be permitted to enter or start to leave until the lock gates are at rest within the gate recesses.

(j) Draft of vessels.-No vessel shall attempt to enter a lock unless its draft is at least 3 inches less than the least depth of water over the guard sills, or over the gate sills if there be no guard sills. Information concerning controlling depth over sills can be obtained from the lock master at each lock or by inquiry at the office of the district engineer of the district in which the lock is located.

(k) Mooring at locks. All vessels when in the locks shall be moored as directed by the lock master. Steamboats and other craft in general shall be moored with bow, stern and spring lines to the snubbing posts provided for that purpose, and in case of a towboat accompanying the tow during a lockage, a line attached to a capstan shall be used

and kept taut, when directed by the lock master, to prevent the tow from running in the lock chamber. Tying to lock ladders is strictly prohibited. Mooring of unattended or nonpropelled vessels or small craft at the upper or lower channel approaches will not be permitted within 1,200 feet of the lock.

(1) Unnecessary delay at locks.-Masters and pilots must use every precaution to prevent unnecessary delay in entering or leaving locks. Wessels failing to enter locks with reasonable promptness when signaled to do so shall lose their turn. Boats arriving at the locks with their tows in such shape as to impede lockage shall lose their turn. Leaking boats may be excluded from the locks until they have been put in such condition that it is, in the opinion of the lock master, safe to pass them through.

(m) Damage to locks or other structures.-The regulations contained in this section shall not affect the liability of the owners and operators of floating craft for any damage caused by their operations to locks or other structures. The sides of all craft passing through any lock shall be free from projections of any kind which might injure the lock walls. Steamboats shall be provided with suitable fenders. One or more men as the lock master may direct shall be kept at the head of every tow until it has cleared the lock and guide walls to protect the walls by use of fenders.

(n) Handling machinery. At locks provided with power no one but employees of the United States will be permitted to move any valve, gate, or other lock machinery. At locks operated by hand the valves, gates, or other lock machinery will be operated only by or under the direction of employees of the United States. Tampering or meddling with the machinery or other parts of the lock is strictly forbidden.

(0) Refuse in locks. The placing of ashes, refuse, or obstructions of any kind in the locks or on the walls thereof or in the canals or on the banks of canals is prohibited. The passing of coal from barges or flats while in the locks is prohibited.

(p) Damage to construction work. To avoid damage to plant and structures connected with the construction or repair of locks and dams, vessels passing structures in the process of construction or repair shall reduce their speed and navigate with special caution while in the vicinity of such work.

(q) Trespass on lock property.-Trespass on locks or dams or other United States property pertaining to the locks or dams is strictly prohibited. Parties committing any injury to the locks or dams or to any part thereof will be responsible therefor. Any person committing a willful injury to any United States property will be prosecuted. No fishing will be permitted from lock walls, guide walls, or guard walls of any lock.

(r) Commercial statistics.-Masters of vessels shall furnish in writing to lock masters such statistics of passengers and cargo carried as may be required.

(s) Flood.-Vessels navigating these waters at flood stages, when passing habitations or other structures, partially or wholly submerged and subject to damage from wave action, shall proceed slowly and keep as far away from such structures as circumstances permit, and shall also proceed slowly when passing close to levees.

(t) Passing movable dams.-When a dam is being raised or lowered all passing craft must use the lock until signaled that the pass is clear. Vessels desiring to wait to use the pass must remain above the head of the lock.

(u) Approach to movable dams.-When dams are up all vessels in the upper pools not intending to enter locks are forbidden to approach nearer to the dams than a line extending across the river from the head of the upper guide wall unless authorized to do so by the lock

master.

(v) Navigation lights for use at all locks and dams except on the Little Kanawha, Big Sandy, Muskingum, Kentucky, Green, Barren, and Rough Rivers, and the Illinois and Mississippi Canal.-(1) At locks at all fixed dams and at locks at all movable dams when the dams are up so that there is no navigable pass through the dam, the following navigation lights will be displayed during hours of darkness:

Three green lights visible through an arc of 360° arranged in a vertical line on the upstream end of the river (guard) wall unless the intermediate wall extends farther upstream. In the latter case, the lights will be placed on the upstream end of the intermediate wall.

Two green lights visible through an arc of 360° arranged in a vertical line on the downstream end of the river (guard) wall unless the intermediate wall extends farther downstream. In the latter case, the lights will be placed on the downstream end of the intermediate wall. A single red light visible through an arc of 360° on each end (upstream and downstream) of the land (guide) wall.

If one or more beartraps or weirs are open or partially open, which may cause a set in current conditions at the upper approach to the locks, this fact will be indicated by displaying a circular disk 5 feet in diameter, on or near the light support on the upstream end of the land (guide) wall during the hours of daylight, and will be indicated during hours of darkness by displaying a white (amber) light vertically under and 5 feet below the red light on the upstream end of the land (guide) wall.

(2) At movable dams when the dam has been lowered or partly lowered so that there is an unobstructed navigable pass through the dam, the navigation lights indicated below will be displayed during hours of darkness until lock walls and weir piers are awash.

Three red lights visible through an arc of 360° arranged in a vertical line on the upstream end of the river (guard) wall.

Two red lights visible through an arc of 360° arranged in a vertical line on the downstream end of the river (guard) wall.

A single red light visible through an arc of 360° on each end (upstream and downstream) of the land (guide) wall.

After lock walls and weir piers are awash they will be marked as prescribed in (x) below.

(w) Navigation lights for use at locks and dams on Little Kanawha, Big Sandy, Muskingum, Kentucky, Green, Barren, and Rough Rivers, and the Illinois and Mississippi Canal. A single red light visible through an arc of 360° shall be displayed during hours of darkness at each end of the river wall or extending guard structure until these structures are awash.

(x) Buoys at movable dams.-Whenever the river (guard) wall of the lock and any portion of the dam are awash, and until covered by a depth of water equal to the project depth, the limits of the navigable pass through the dam will be marked by buoys at the upstream and downstream ends of the river (guard) wall, and by a single buoy over the end, or ends, of the portion or portions of the dam adjacent to the navigable pass over which project depth is not available. A red nuntype buoy will be used for such structures located on the left-hand side (facing downstream) of the river and a black can-type buoy for such structures located on the right-hand side (facing downstream) of the river, buoys to be lighted if practicable.

Where powerhouses or other substantial structures projecting considerably above the level of the lock wall are located on the river (guard) wall a single red light located on top of one of these structures may be used instead of river wall buoys prescribed above until these structures are awash, after which they will be marked by a buoy of appropriate type and color (red nun or black can buoy) until covered by a depth of water equal to the project depth, buoys to be lighted if practicable.

(y) Vessels to carry regulations.-A copy of these regulations shall be kept at all times on board each vessel regularly engaged in navigating the rivers to which these regulations apply. Copies may be obtained from any of the lock offices on request.

(z) Penalty. The penalty for violating these rules and regulations is $500 fine or not exceeding 6 months' imprisonment.

(aa) Effective date. These regulations shall be in force and effect on and after February 1, 1933, and shall supersede all regulations heretofore issued for the Ohio River and the Mississippi River above Cairo, or any part thereof, or for any of their tributaries in conflict therewith.

GENERAL REGULATIONS

6

Pursuant to the provisions of section 7 of the River and Harbor Act of August 8, 1917 (40 Stat. 266; 33 U. S. C. 1),5 the following regulations have been prescribed to govern lights and day signals to be displayed in certain cases and the passing by other vessels of floating plant working in navigable channels.

201.1 Scope and applicability of regulations.-(a) The regulations contained in this part govern lights and day signals to be displayed by towing vessels with tows on which no signals can be displayed, vessels working on wrecks, dredges, and vessels engaged in laying cables or pipe or in submarine or bank protection operations, lights to be displayed on dredge pipe lines, and day signals to be displayed by vessels of more than 65 feet in length moored or anchored in a fairway or channel, (secs. 201.2 to 201.9, inclusive), and the passing by other vessels of floating plant working in navigable channels (secs. 201.10 to 201.16, inclusive).

(b) The regulations contained in this part are applicable on the Great Lakes and their connecting and tributary waters as far east as Montreal ("Great Lakes"), and on the Red River of the North and

4 Code of Federal Regulations, Title 33, Chapter II, Part 201.

Prescribed December 24, 1947, effective March 1, 1948.