Navigation Dimensions
Shannon
Length of locks: 29.2m
Beam of locks: 5.75m
Draft: 1.35m
Air draft Variable*
Lough Allen
Length of locks: 19.5m
Beam of locks: 4m
Draft: 1.2m
Air draft: 3m
Draft dimensions are given as a guide only and cannot be guaranteed. Owners of deep-drafted craft, greater than 1.2m should contact the Inspectorate before travelling.
Navigation Rules, to be used in conjunction with the online Shannon Navigation Guide
1) Always keep to the marked channel. A lateral system of marks and buoys laid from Limerick City northwards aid navigation along the waterway. Green marks with a Rectangular Topmark indicate the right hand side of the navigable channel while Red marks with a Circular Topmark indicate the left hand side.

When going upstream therefore, Green will be on your right and Red on your left.

Coming downstream, Green will be on your left and Red on your right.
Additionally, the large buoys on Lough Derg bear an identification Letter (A to J) while on Lough Ree they bear an identification Number (1 to 9). This system of marks and buoys used in conjunction with the official Navigation Guides (Printed or Online) and the most recent information published in Waterways Ireland's Marine Notices (visit www.waterwaysireland.org) will assist you in safely navigating this waterway.
Various other navigation markers are also used on the Shannon:-
White Pillars – These are based on shore and act as a point of reference for navigating only.
Air Draft Gauges– Be aware of air draft restrictions, for example when travelling under bridges.
End of Navigation – Do not proceed beyond this point.
2) Always maintain a good look-out for other users such as swimmers, canoeists, sailors etc when navigating the waterway.
3) Keep to the marked navigation arch when negotiating bridges. Use the arch on your right when more than one arch is navigable.
4) Keep a good distance off all navigation markers. Keep clear of weirs.
5) It is an offence to exceed 5km/h within 200m of a bridge or jetty, within 100m of a lock, in a canal or harbour or when passing within 100m of a moored vessel. Reduce speed when passing swimmers, anglers and small boats.
6) Ensure that you have adequate headroom when passing under bridges. If in doubt at Roosky and Tarmonbarry, request that the bridges be raised. Portumna Bridge must be opened and the Lough Allen Canal footbridge must be raised.
7) When crossing the major lakes, establish your position by checking the numbers on the large buoys in Lough Ree and the letters on the similar buoys in Lough Derg with those on the accompanying printed and online guides.
8) When proceeding from one navigation marker to another, keep an eye on the one behind as the wind may cause you to drift inside the line.
9) Ensure that the mooring ropes do not trail in the water as they may foul the propeller.
10) If your vessel has a draft in excess of 1.7m you may not navigate without express permission.
11) It is an offence to navigate a vessel when under the influence of drugs or alcohol.
12) Always keep a good look-out and navigate with care and caution and with reasonable consideration for others.
13) When meeting an approaching vessel, keep to the right of the channel so that you pass each other on the left side.
14) If you meet a vessel crossing from your right and there is danger of collision, you must give way.
15) When going upstream at a bridge, give way to vessels coming downstream.
16) When overtaking, leave the other vessel on your right hand side. You must keep out if its way when doing so and it must leave you sufficient room to overtake.
17) You must give way to vessels under sail.
18) Approach locks slowly and keep out of the way of vessels existing. When in a lock do not refuel and do not light a cooker or any appliance with a naked flame. When there is more than one vessel in the lock, switch off your engine. When leaving the lock, do so at a slow speed.
19) You may not berth at a particular quay or harbour for more than 5 consecutive days or more than a total of 7 days in any one month.
20) It is an offence to moor at any navigation mark.
21) When navigating at night, your vessel must be equipped with lights as specified in the Bye-laws.