If you’ve noticed your boat scraping bottom at low tide, or your lift struggling to clear the muck, sediment buildup is probably to blame. In Palm Beach and Broward County, sediment gradually builds up in a slip as tides, storms, and runoff carry sand and silt toward the shoreline steadily reducing the water depth available to your boat, often without anyone noticing until the boat stops floating level.
Here’s what actually determines how deep your slip needs to be, what dredging a boat slip costs, and how the process restores that depth.
How Much Depth Does a Boat Slip Actually Need?
The starting point is your boat’s draft the distance from the waterline to the lowest point of the hull, prop, or outdrive. Whatever that number is, your slip needs more water than that at its shallowest point which in tidal waterways means checking depth against mean low water (MLW), the tidal datum based on the average of low-tide water levels, rather than the water level at high tide.
It is recommended that you have a clearance of 1 to 2 feet under the lowest point of your boat during the lowest tidal period. You may need additional clearance when your boat has fixed propellers, stern drives, or swing keels or when there is a muddy bottom because of the accumulation of mud and debris due to the cleaning process. For instance, if your boat has a draft of 3 feet in the water, your dock location needs to have at least 4 to 5 feet of clearance in the low tidal period. Otherwise, your boat will bottom out when the tide is out.
Since all vessels reach varying depths, and each area has different water depths and bottoms, there is no way to know what the right depth is except by measuring the depth of the water in your particular area. Water depth measurements have to be done first and foremost before doing any dredging operations.
What Does Boat Slip Dredging Cost?
Dredging is priced by the cubic yard, and the range is wide because the job conditions vary so much. In Florida, per-yard pricing typically runs $100 to $300, depending on sediment type, access, and disposal requirements.
| Cost Driver | Why It Matters |
|---|---|
| Sediment type | Clean sand costs far less to remove and dispose of than muck, clay, or contaminated sediment |
| Access | Shore-based equipment (like a track hoe) is cheaper than barge-mounted or hydraulic suction dredges brought in for tight or deep-water sites |
| Volume | Small residential slips carry higher per-yard costs than larger jobs, since mobilization costs get spread over less material |
| Disposal distance | Trucking or barging spoil to an approved site adds cost as distance increases |
| Permitting complexity | Sites near seagrass, manatee habitat, or environmentally sensitive waters require more documentation and review time |
The only way to know for sure is to do a site survey: the amount of sediment, nature of the bottom, and accessibility must all be measured, not estimated.
How Boat Slip Dredging Works?
- The contractor will determine water depth, amount of sediments and bottom make-up near your slip/lift location and confirm your desired depth of dredging based on the draft of your boat.
- Dredging in Florida may require an Environmental Resource Permit (ERP), depending on the project, location, and scope of work and some also require permits from the U.S. Army Corps of Engineers through the Rivers & Harbors Act and the Clean Water Act. Dredging maintenance of an existing man-made canal to its already permitted depth may be eligible for an exemption in certain cases, but that is to be determined on a case-by-case basis with FDEP; it is not a guaranteed exclusion.
- In the case of smaller slips that can be reached from shore, this may be done from shore by suction dredging. Other sites that are tighter and have deeper water may require the use of hydraulic suction dredging, depending on site conditions. See how this applies specifically to lifts on the boat lift dredging.
- Removed material (“spoil”) may need to be dewatered and hauled to an approved disposal or reuse site; it can’t just be pushed onto the yard or left in a canal, depending on the project requirements. Once that’s done, the site is cleaned up and ready to use.
A small residential slip can often be completed in a day or two once permits are in hand; the permitting stage is usually what determines the overall project timeline, not the dredging itself.
Signs Your Slip Needs Dredging
- Keel, propeller, or lift is making contact with the bottom, especially during low tide.
- Lift is struggling or grinding while trying to raise and lower the boat.
- The water is visibly shallow in comparison with the main channel or canal.
If any of these is relevant to your situation, then depth testing is your best option; the only way to know if the problem is just some inches of buildup or what equipment is required.
Coastal Dredging provides boat slip, dock, and boat lift dredging throughout Palm Beach and Broward County. We can guide you through your permitting options and refer you to trusted permitting companies when needed.
Book a free consultation to get an accurate depth read and a real cost estimate for your property.
