erroneous non-equal coverage warning

[LHMarshall]

The following design (total sampler number supplied and systematic designs in both strata) will give equal coverage but there is a warning saying that it probably won't. By creating a set of transects we can verify that in fact the spacing values are identical for both strata meaning that the spacing was calculated globally and therefore we will achieve uniform coverage between strata (excluding edge effects)

> equal.cover <- make.design(region = northsea,
+                            transect.type = "line",
+                            design = "systematic",
+                            samplers=40, 
+                            design.angle = c(50, 40),
+                            truncation = 0.8,
+                            coverage.grid = coverage.grid)
Warning: The default allocation of samplers to strata (i.e. the number of samplers per stratum are in proportion to stratum areas) will likely lead to an unequal effort design as average sampler lengths will likely vary between strata.
> tmp <- generate.transects(equal.cover, northsea)
> tmp

   Strata South:
   ______________
Design:  systematically spaced parallel transects
Spacing:  19.62722
Line length: 3261.307
Trackline length: 3784.83
Cyclic trackline length: 4124.466
Number of samplers:  17
Design angle:  50
Edge protocol:  minus
Covered area:  5205.972
Strata coverage: 8.16%
Strata area:  63832.19

   Strata North:
   ______________
Design:  systematically spaced parallel transects
Spacing:  19.62722
Line length: 5884.431
Trackline length: 6667.862
Cyclic trackline length: 7105.306
Number of samplers:  23
Design angle:  40
Edge protocol:  minus
Covered area:  9400.26
Strata coverage: 8.1%
Strata area:  116016.1

   Study Area Totals:
   _________________
Line length: 9145.738
Trackline length: 10452.69
Cyclic trackline length: 11229.77
Number of samplers:  40
Covered area:  14606.23
Average coverage: 8.12%