How to Map Marina Slips and Berths with GIS

A marina slip is not just a number in a ledger — it is a specific physical space with exact dimensions, a known depth, particular amenities, and a precise location relative to the dock entrance, the fuel dock, and the marina office. A number on a spreadsheet captures almost none of that information.

A GIS-based slip map captures all of it. Every slip is a polygon with its actual boundaries drawn accurately on satellite imagery, and every attribute — length, beam clearance, depth, power service, current tenant, lease status — is attached to that polygon and searchable.

This guide explains how to build a marina slip map in Atlas that works as a genuine operational tool, not just a visual diagram.

Why a Visual Slip Map Changes Daily Operations

Marina staff who work from a visual slip map consistently report the same benefits:

• Fewer assignment errors — staff can see at a glance that a 55-foot boat in slip 43A would block the fairway, or that a deep-draft vessel would be dangerously shallow in the inner basin
• Faster guest guidance — "you're in slip 27B, which is the third finger off the main dock on your starboard side" is easier when you're looking at a map
• Better utilization — vacant slips are immediately visible spatially, revealing clusters of vacancy that might be better served by reorganizing slip categories

Step 1: Set Up Your Layer Structure

Open Atlas and create a new marina project. Set the basemap to satellite imagery — your marina is visible in the aerial view and gives you the reference you need to draw slips accurately.

Create separate layers for each category of space:

• Slips - Seasonal — permanent lease berths
• Slips - Transient — short-term guest berths
• Slips - Dry Stack — for marinas with dry storage
• Mooring Fields — if applicable
• Docks and Piers — the fixed and floating dock infrastructure

Keeping these separate lets you style them differently and share only the relevant layers with different audiences.

Step 2: Trace the Marina Layout

Start by tracing the dock fingers and main docks as line or polygon features. Zoom into the satellite imagery enough to see individual pilings and dock edges. The satellite imagery for most established marinas is detailed enough to trace dock layouts with reasonable accuracy.

If you have as-built drawings of the marina — even paper ones — scan and georeference them as a reference layer in Atlas to trace over.

Step 3: Draw Individual Slip Polygons

For each slip, use the polygon draw tool to trace:

• The entrance (channel-facing edge of the slip)
• Both side edges (along the finger piers)
• The back wall or hammerhead

The resulting polygon represents the actual water space of that slip. Trace it as precisely as the imagery allows — the polygon shape directly informs the dimensional data you'll add as attributes.

Step 4: Add Slip Attributes

Click each slip polygon to open its properties panel. Add these attributes:

The status attribute is the one you'll update most frequently. Coding it as a color on the map — green for vacant, blue for seasonal, orange for transient, red for maintenance hold — turns your map into a live occupancy dashboard.

Step 5: Style Slips by Status

In Atlas, apply a style rule to each slip polygon based on the status attribute:

• Vacant: green fill
• Seasonal occupied: blue fill
• Transient: orange fill
• Reserved: purple fill
• Maintenance hold / Out of service: gray fill

This color coding means anyone looking at the map can immediately read occupancy across the entire marina without clicking individual slips.

Step 6: Add Depth Overlay

Overlay your slip map with a depth layer. If you have a recent bathymetric survey, import the data into Atlas as a raster or contour layer. Style it with a color ramp from deep (dark blue) to shallow (light blue/white).

With both slip polygons and depth visible, you can:

• Visually identify which slips might be marginal for deep-draft vessels at low tide
• Prioritize which areas need dredging
• Add depth-at-MLW as an attribute on each slip polygon for searchable filtering

Step 7: Share with Your Team

Invite your dock master, front desk staff, and assistant managers to the Atlas project with appropriate access:

• Full edit access: senior dock staff who update slip status
• View-only access: front desk staff who need to see occupancy to answer customer calls
• Temporary shared link: contractors or guest dock staff covering specific periods

The map is accessible on any device — desktop in the office, tablet at the dock master's station, phone for staff walking the docks.

Using the Slip Map for Assignment Decisions

When a customer calls asking for availability, your dock staff can:

1. Open the map and filter by status: "show me all vacant slips"
2. Filter by vessel requirements: "vacant slips rated for 45 feet and above"
3. Visually assess location — is it close to the guest's preferred basin? Is it near the fuel dock?
4. Confirm depth compatibility with the vessel's draft

This process takes 30 seconds from a GIS map versus 3–4 minutes browsing a spreadsheet and cross-referencing depth records.

Maintaining the Map Over Time

A slip map is only useful if it stays current. Build these habits:

• Update status immediately when a boat arrives or departs
• Update depth attributes after each dredging event or survey
• Review lease end dates monthly and flag slips approaching vacancy
• Archive old tenant data at the end of each season to maintain a searchable history

Your GIS slip map becomes the most reliable, always-current operational reference your marina has — and unlike a spreadsheet, it never loses its spatial context.