Dock/harbour tools construct a marine and waterway transport network. Tools may build or remove: canals, locks, various docks, and a ship depot. If playing with timeline, then as time passes in Simutrans more tool options may appear.

Click boat-icon at top of the main game window to open toolbar.
Hover the mouse cursor over a toolbar icon (after opening or clicking on toolbar) to see name and where appropriate: construction cost, maintenance cost in brackets, and maximum speed and weight limits.

Dock/harbour tools include, from left to right:

Canal: tool builds waterways, for boats and barges, between two points in the main game window.
Canals can only be built on slopes in the direction of the slope and may not find a path across rough terrain. Canals built between points, may use existing canal in its path.
To build a canal: click on the tool icon to select (changes cursor to canal), then click on terrain for start-point (shows a bulldozer in the main game window and map co-ordinates on right of bottom-bar under the main game window), and finally click on terrain for end-point.
Tip: Canals built by different players may not connect. Use Landscape tools to change terrain, to enable paths for canals. Use the destroy/remove tool to remove individual pieces of canal and some obstructions. Undo last route connection [z] does not refund constructions costs.

Remove channels: tool removes portion of canal, when no vehicles are present, between two points in the main game window (NB: Channel-stops in path are removed too). The tool has an associated construction cost.
To remove canal: click on the tool icon (changes cursor to a cross); then click on canal that is to be deleted (selects deletion-point shown by a red cross in the main game window); and finally click at another point on canal, to remove portion up to first deletion-point.

Ship Hoist: tool builds a canal lock and bridge to raise/lower a boat or barge by one level on a canal in the main game window. The bridge has a maximum span and is built on the end of a canal to a suitable place (another canal-end or slightly higher land, within span).
To build bridge: click on the tool icon to select bridge (changes cursor to hoist), then click on the end of a canal, (starting-point of bridge). Some obstructions or lack of a suitable place for bridge-ends may stop hoist being built: build canal at both sides that is to be bridged, and try again.
Tip: Use the destroy/remove tool to remove bridges (click on hoist-end) and some obstructions to bridge building.
Use Canal tools to connect bridge-ends to water ways..

Wharf (Canal Quay in pak128) tool builds a dock on a canal in the main game window for water-transport-vehicles to pick up and drop off cargo and passengers.
A dock when not built adjacent to an existing Stop will create a new Stop.
A dock has a catchment area for goods, passengers and mail. In the corner of the a toolbar icon is an icon (used in Station List and Stop Information) shows which items the dock allows a Stop to handle.
To build a dock: click on the tool icon (changes cursor to a channelstop); then click on a canal in the main game window to construct.
Tip: Remove docks with the destroy/remove tool. Press [v] to show/hide catchment area for goods and passengers in the main game window.
Stops just for water transport vehicles will not be listed in ?Stops/Station list.

Ship-stops: tools build various items that construct docks in the main game window for water-transport-vehicles to pick up and drop off cargo and passengers.
Docks are built at edges of straight coast.
A dock when not built adjacent to an existing Stop will create a new Stop.
Docks have a catchment area for goods, passengers and mail. In the corner of the a toolbar icon is an icon (used in Station List and Stop Information) that shows which items the dock allows a Stop to handle. Different docks may have different capacities for goods, passengers and mail.
To build a dock: click on the tool icon to select (changes cursor to a dock) and then click on a slope by water to build
Tip: Remove docks with the destroy/remove tool.
Size of docks can be increased by building on adjacent squares. Water-transport vehicles may use any square of water in the catchment area of a dock.
Stops just for water transport vehicles will not be listed in ?Stops/Station list.
Off-shore Industry such as Oil Rigs do not require a dock, water-transport vehicles may use any square of water in the catchment area of an off-shore Industry.
Press [v] to show/hide catchment area for goods and passengers in the main game window.

Ship Depot: tool builds a depot for purchasing and managing ships, boats and barges. Depots have a maintenance cost and are built on water in the main game window.
To build a ship depot: click on the tool icon (changes cursor to a depot), then click on water in the main game window.
Tip: Remove depots with the destroy/remove tool.