Coverage · St. Croix
Construction survey on St. Croix, at scale.
Roughly eighty-four square miles — more land than St. Thomas and St. John together — and the only island in the territory where the survey problem is usually area rather than access. Open parcels, long corridors, and an industrial south shore, flown in mobilizations planned around covering ground.
Scale and terrain
The island where area is the problem.
Everywhere else in the territory the hard part is reaching the site. Here it is covering it.
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Large parcels and open land
Agricultural and undeveloped ground in blocks that a ground crew measures in days. A parcel that takes a two-person crew most of a week to walk is a single flight with the control set in the morning, and the deliverable is a continuous surface rather than a scatter of shots joined by assumption.
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Comparatively flat, and that matters
Relief here is gentle next to the northern islands. Flat ground lets the aircraft hold a consistent altitude, which holds ground sample distance consistent across the whole capture. It is the single biggest reason coverage per day is higher on this island than anywhere else we work.
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The industrial south shore
Heavy industrial and port facilities along the southern coast, where the survey is routine and the access is anything but. Operator induction, escort requirements, and restrictions on when anything may be flown are set by the facility, and they belong in the proposal rather than in a conversation at the gate.
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Roadway and utility corridors
Long alignments running the length of the island. A corridor is the worst shape a ground crew can be handed — narrow, linear, and mostly distance between the measurements that matter. Flown in one pass it becomes a continuous surface with the sections and profiles a civil team designs against.
Two of those four change the shape of the proposal rather than just its price. A corridor is scoped by length rather than area, which is why it sits under aerial mapping rather than being quoted as a parcel. And an industrial site is scoped around the operator’s access regime before anything else, which is a conversation worth having at the same time as the compliance question rather than after it.
Airspace
Henry E. Rohlsen,
settled before we travel.
The Class D surface area around Henry E. Rohlsen sits over the south-central part of the island, which is where a good deal of the industrial and corridor work is. On an island a crew has to cross water to reach, getting that wrong costs more than a wasted morning.
- Resolved before the mobilization is booked. Not before the flight — before the travel. An airspace problem found on site here has cost a crossing.
- Alignment, not just address. A corridor can begin outside the surface area and run into it, so the question here is which part of the route is affected rather than whether the site is. We answer it against the alignment.
- FAA Part 107 throughout. Inside controlled airspace and out.
- Facility restrictions are separate. An industrial operator can restrict flight over its own site regardless of what the airspace permits. Both get settled at scoping.
Getting to your site
A St. Croix job is its own mobilization.
We are based at Red Hook on St. Thomas. St. Croix is roughly forty miles south across open water, which means a job here moves crew and equipment rather than driving to a site. That is a scheduled, priced line in the proposal, and we will not pretend otherwise: this island is booked, not called out, and nothing on this page should be read as offering same-day attendance.
Said plainly because the alternative is worse. A vendor who implies island-wide immediacy from an office on another island is setting up the conversation you will have on the day it matters. What we can commit to is a date agreed in advance and a day planned around covering ground, which on parcels this size is where the value actually is.
Construction layout and staking runs with survey crews mobilized from the mainland, working Trimble total stations. It has to be scheduled in advance and it is priced against that mobilization. It is not an on-demand local call-out, and we will not describe it as one. How it is scoped sits on the drone survey page.
One practical consequence worth planning around: because the crossing is the fixed cost, St. Croix jobs reward batching. If you have three parcels, a corridor, and a progress capture due in the same month, scoping them together costs materially less than three separate crossings.
What we do here
Four disciplines, priced by the acre.
Area, corridors, and industrial access change what each one costs and what it is worth.
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/01
Drone Survey
Large-parcel topographic survey is where flying stops being a convenience and becomes the only sensible way to buy the measurement. Open ground, consistent altitude, one control set, and a surface across the whole parcel rather than a traverse through it.
Drone survey services → -
/02
Aerial Mapping
Corridor mapping is the St. Croix product. A roadway or utility alignment captured in a single pass yields the orthomosaic, the surface, and the cross-sections together, which is a different proposition from covering the same distance on foot.
Aerial mapping services → -
/03
360° Job Walkthrough
Longer programmes and more parties on the contract, which is what industrial and institutional work looks like here. More parties means more positions to reconcile later, and a dated interval series is what reconciles them.
360° walkthrough services → -
/04
Scan to BIM
Industrial plant and institutional buildings with long service runs and repeated fit-out cycles. The mechanical model is usually why the scan is commissioned, and on this island it is usually why it pays.
Scan-to-BIM services →
By site type
What each kind of St. Croix job drives.
Cost on this island tracks area, length, or access, and rarely more than one at a time. The middle column is which.
| Site type | What drives the cost | What the job usually needs |
|---|---|---|
| Agricultural and open parcel | Acreage, and the ground sample distance the deliverable needs | Single-mobilization flight, full-parcel surface, contours at your interval |
| Large-lot subdivision | Total area plus the number of separate surfaces wanted | Existing-ground surface, design comparison, staged progress topo |
| Roadway corridor | Alignment length, not width | Corridor flight, cross-sections and profiles, DWG or LandXML handoff |
| Utility corridor | Length, plus access permission along the alignment | Corridor capture with clearances measured off the surface |
| Industrial south shore facility | Operator induction, escort, and permitted flight windows | Induction and escort arranged first; flight windows fitted around plant operations |
| Port and terminal | Facility-controlled access and vessel operations | Windows agreed around operations; aerial plus terrestrial where quays are involved |
Questions we get
About working on St. Croix.
How does a St. Croix job get scheduled?
As its own mobilization, agreed at proposal. The office is at Red Hook on St. Thomas and St. Croix is roughly forty miles south across open water, so crew and equipment travel and that travel is a scheduled, priced line rather than something absorbed quietly.
Nothing about that is a disadvantage once the day is planned properly. It does mean a St. Croix job is booked rather than called out, and we would rather you had that in the proposal than discover it when you need a crew at short notice.
How much ground can you cover in a day here?
More than anywhere else in the territory, which is most of why the economics work on this island. Open, comparatively flat parcels let the aircraft hold a consistent altitude and fly long lines, and both of those things are what actually drive coverage.
The variables are the ground sample distance the deliverable needs, how much relief the parcel carries, and airspace. The proposal states the area and the number of days rather than leaving it open-ended.
Is authorization needed near Henry E. Rohlsen?
Inside the Class D surface area, yes, and it is resolved before the mobilization is booked rather than on the morning of the flight.
Because a St. Croix job already travels, airspace matters differently here than on an island you can drive to in twenty minutes: an authorization problem discovered on site has cost a crew a crossing, not a drive. That is a large part of why the airspace position is settled at proposal on this island in particular.
Can you capture a road or utility corridor in one pass?
Yes, and on this island that is frequently the entire reason to fly. A corridor is the worst possible shape for a ground crew: long, narrow, and mostly walking between the measurements that matter.
Flown, the same alignment produces a continuous surface with the cross-sections and profiles your civil team works from, captured in one mobilization instead of a sequence of days spent covering distance. The product detail is on aerial mapping.
Do you work inside the industrial facilities on the south shore?
The survey work is within scope. The access is set by the operator, and that is the part worth settling before anything is booked.
Industrial sites run their own induction, escort, and permit-to-work requirements, and their own restrictions on when and where anything may be flown. Those are the facility’s rules rather than ours. Tell us which facility and which areas at scoping, and the proposal states what the capture depends on rather than leaving site access to be sorted out on the morning.
North of here
The northern group is a different job.
Smaller, steeper, and reachable from the office without a crossing. The constraints invert.
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St. Thomas
Where the office is, and where access rather than area is the constraint: benched hillside lots, a dense historic core, and single-lane approaches that decide where a crew can even stage.
Construction survey on St. Thomas → -
St. John
The smallest of the three and the most constrained: protected land drives the flight plan, tree cover widens the gap between a canopy surface and bare earth, and equipment arrives by barge on somebody else’s timetable.
Construction survey on St. John →
Tell us about the site.
Send the island, the parcel, and what you need out the other end. We’ll come back with a scoped, fixed-fee proposal within one business day.