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 game-view to open toolbar.
Hover mouse-cursor over tool-option (after opening or clicking on toolbar) to see name & where appropriate: construction cost, maintenance cost in brackets, and maximum speed limit.

Dock/harbour tools include, from left to right:

Canal: tool builds waterways, for boats and barges, between two points in game-view.
Canals can only be built on slopes in the direction of the slope & 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 tool to select (changes cursor to canal), then click on terrain for start-point (shows a bulldozer in game-view and map co-ordinates on right of bottom-bar under game-view), & finally click on terrain for end-point.
{Tips: Canals built by different players may not connect. Use Landscape tools to change terrain, to enable paths for canals. Use Destroy/Remove to remove individual pieces of canal & 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 game-view (NB: Channel-stops in path are removed too). The tool has an associated construction cost.
To remove canal: click on tool (changes cursor to a cross); then click on canal that is to be deleted (selects deletion-point shown by a red cross in game-view); & 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 game-view. 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 tool 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, & try again.
{Tips: Use Destroy/Remove to remove bridges (click on hoist-end) & 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 game-view 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 & mail. In the corner of the tool-option is an icon (used in Station List & Stop Information) shows which items the dock allows a Stop to handle.
To build a dock: click on tool (changes cursor to a channelstop); then click on a canal in game-view to construct.
{Tips: Remove docks with Destroy/Remove. Press [v] to show/hide catchment area for goods and passengers in game-view.
Stops just for water transport vehicles will not be listed in ?Stops/Station list}.

Ship-stops: tools build various items that construct docks in game-view 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 & mail. In the corner of the tool-option is an icon (used in Station List & Stop Information) that shows which items the dock allows a Stop to handle. Different docks may have different capacities for goods, passengers & mail.
To build a dock: click on tool to select (changes cursor to a dock) and then click on a slope by water to build
{Tips: Remove docks with Destroy/Remove.
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 game-view.}

Ship Depot: tool builds a depot for purchasing & managing ships, boats and barges. Depots have a maintenance cost & are built on water in game-view.
To build a ship depot: click on tool (changes cursor to a depot), then click on water in game-view.
{Tips: Remove depots with Destroy/Remove.}