SOUNDING-bgol (Bathymetric Sounding Notation)

Command Type: AutoLISP routine (works in AutoCAD, BricsCAD, ZWCAD and most AutoLISP-compatible CAD platforms)
Developed by: BGol Community, bgol.in

Inspired by the general concept of bathymetric sounding notation used in hydrographic survey drafting. This is an original, independently written routine, new file name, new command name, new source code, created so the CAD community has a free, editable, open-source alternative.

Overview

SND converts plain decimal elevation/depth text (e.g. 82.64) into traditional bathymetric sounding notation: the whole-number part shown large and bold, with the decimal digits shown as a smaller under-script numeral beside it, the standard cartographic convention for water-depth soundings on nautical and hydrographic charts.

How to Use

1. Load SOUNDING-bgol.lsp into your CAD session (drag-and-drop the file onto the drawing window, or use the APPLOAD command).
2. Type SND at the command line and press Enter.
3. Select one or more TEXT entities holding plain decimal depth values.
4. For each selected text, an integer-part label (larger, blue) and a decimal under-script label (smaller, yellow, offset down-right) are created near the original position, on layer BGOL-SND. The original text entities are left untouched.

Why Use It

• Chart-standard notation, produces cartographically correct bathymetric/sounding notation automatically, matching the international convention used on nautical and hydrographic charts.
• Saves manual re-styling, avoids significant manual text-formatting effort when converting a land-style elevation dataset into chart-standard soundings.
• Consistency, ensures visual consistency across all sounding labels on a bathymetric map.

Where to Use It

• Producing bathymetric maps / hydrographic survey drawings of oceans, seas, ponds, reservoirs, or lakes, where water depth needs to be shown in standard sounding notation.
• Converting depth-sounding data captured via echo sounder / depth sounding equipment into properly formatted chart labels.
• Any marine, coastal, or reservoir survey deliverable that must follow conventional bathymetric chart symbology.

Notes

• Decimal digits are right-padded to a 4-digit sounding tag (e.g. .64 becomes 6400), matching the common chart-sounding style shown on the reference examples.
• Integer-part labels use color 5 (blue) and decimal under-script labels use color 2 (yellow) by default to visually distinguish the two parts.
• Works on any TEXT entity containing a decimal number; text without a decimal point is treated as a whole-number sounding with a 0000 tag.
• Source code is fully open, feel free to study, modify, and redistribute it under the same open, free-for-all spirit.

Credits

Developed and shared for the CAD community by BGol Community. Website: https://bgol.in/ Free and open-source, use it, modify it, share it, for personal or commercial work alike.