Why won't my Garmin 922x route through Bøgestrømmen with a 1.65 m draught?
My Garmin 922x will not calculate a route through Bøgestrømmen. The boat draws 1.65 m, so is there a setting stopping it, or does the plotter think the channel is too shallow?
Answer
Your Garmin is probably rejecting Bøgestrømmen because its Auto Guidance depth setting, vertical clearance setting or chart data prevents it finding an acceptable route through the passage. A 1.65 m draught alone does not establish whether the passage is suitable, so check the routing settings and find the exact point where the calculation fails before changing anything.
Check Preferred Depth first
On many GPSMAP units in the 922 family, look under Settings > Navigation > Auto Guidance for Preferred Depth, Vertical Clearance and Shoreline Distance. Names and menu positions vary with software version. Confirm the unit's full model designation, particularly whether it is a 922 or 922xs.
Preferred Depth is the minimum charted water depth you want the calculated route to use. It is not simply the boat's draught, and it is separate from the depth sounder's keel offset.
- Check units: make sure the setting is in metres, not feet.
- Read the stored value: a setting of 2.5 m or 3.0 m can exclude a channel you expected to use.
- Allow under-keel clearance: 1.65 m draught plus an illustrative 0.35 m allowance gives a 2.00 m planning threshold.
That 0.35 m is an arithmetic example, not a clearance recommendation for Bøgestrømmen. Loading, water level, waves, squat and the reliability of the surveyed depth all affect the allowance you need. Do not lower the setting below a defensible minimum just to obtain a route.
Find the rejected section
Calculate several short passages instead of one route across the whole area. Place the start and finish in clearly charted water within the marked channel, first on either side of the suspected obstruction, then progressively farther apart. A start point in shallow water beside a harbour can prevent a calculation even when the main passage is acceptable.
Zoom in until individual soundings, channel edges and bridge information appear. Examine the narrowest section and any point where the proposed route stops or diverts.
A visible sounding does not necessarily mean the routing engine recognises a continuous channel at that depth. It also uses the chart's encoded depth areas and other restrictions. A narrow dredged passage may look usable on screen yet fail the automatic calculation.
A successful calculation does not confirm today's available depth either. Check the current official chart, navigational warnings and relevant Danish harbour or waterway information for shoaling, buoy changes and restrictions.
Check clearance and shoreline distance
If the selected passage includes a bridge, check the charted clearance and the Garmin's Vertical Clearance setting. For a sailing yacht, this means the height above the water of the highest fitted equipment, including aerials and instruments, rather than mast length alone.