diff --git a/src/geodesy/earthtide.c b/src/geodesy/earthtide.c
index 7efc1e35533..ff2f5a591c8 100644
--- a/src/geodesy/earthtide.c
+++ b/src/geodesy/earthtide.c
@@ -1110,7 +1110,7 @@ GMT_LOCAL void earthtide_solid_grd (struct GMT_CTRL *GMT, struct EARTHTIDE_CTRL
 	int k, mjd, year, month, day, hour, min;
 	uint32_t row, col, n_columns = 0, n_rows = 0;
 	size_t ij_n = 0, ij_e = 0, ij_u = 0, n_inc = 0, e_inc = 0, u_inc = 0;
-	float *grd_n, *grd_e, *grd_u;
+	gmt_grdfloat *grd_n, *grd_e, *grd_u;
 	double fmjd, xsta[3], rsun[3], etide[3], rmoon[3];
 	double lat, ut, vt, wt, *lons;
 	double west = 0, south = 0, x_inc = 0, y_inc = 0;
@@ -1122,21 +1122,21 @@ GMT_LOCAL void earthtide_solid_grd (struct GMT_CTRL *GMT, struct EARTHTIDE_CTRL
 		e_inc = 1;
 	}
 	else
-		grd_e = (float *)malloc (1 * sizeof (float));
+		grd_e = (gmt_grdfloat *)malloc (1 * sizeof (gmt_grdfloat));
 
 	if (Ctrl->G.do_north) {
 		grd_n = Grid[Y_COMP]->data;
 		n_inc = 1;
 	}
 	else
-		grd_n = (float *)malloc (1 * sizeof (float));
+		grd_n = (gmt_grdfloat *)malloc (1 * sizeof (gmt_grdfloat));
 
 	if (Ctrl->G.do_up) {
 		grd_u = Grid[Z_COMP]->data;
 		u_inc = 1;
 	}
 	else
-		grd_u = (float *)malloc (1 * sizeof (float));
+		grd_u = (gmt_grdfloat *)malloc (1 * sizeof (gmt_grdfloat));
 
 	/* Get header params. Since all three have the same dims we stop when we find the first grid required */
 	for (k = 0; k < N_COMPS; k++) {
@@ -1171,9 +1171,9 @@ GMT_LOCAL void earthtide_solid_grd (struct GMT_CTRL *GMT, struct EARTHTIDE_CTRL
 			earthtide_detide (xsta, mjd, fmjd, rsun, rmoon, etide, &leapflag);
 			/* determine local geodetic horizon components (topocentric) */
 			earthtide_rge (lat, lons[col], &ut, &vt, &wt, etide[0], etide[1], etide[2]);		/* tide vect */
-			grd_n[ij_n] = (float)vt;
-			grd_e[ij_e] = (float)ut;
-			grd_u[ij_u] = (float)wt;
+			grd_n[ij_n] = (gmt_grdfloat)vt;
+			grd_e[ij_e] = (gmt_grdfloat)ut;
+			grd_u[ij_u] = (gmt_grdfloat)wt;
 			ij_n += n_inc;
 			ij_e += e_inc;
 			ij_u += u_inc;
diff --git a/src/gmt_customio.c b/src/gmt_customio.c
index 69a9076d951..5d33641ecfb 100644
--- a/src/gmt_customio.c
+++ b/src/gmt_customio.c
@@ -1177,7 +1177,7 @@ void gmtlib_encode (struct GMT_CTRL *GMT, void *vptr, uint64_t k, gmt_grdfloat z
 			((int *)vptr)[k] = (int)lrintf (z);
 			break;
 		case 'f':
-			((float *)vptr)[k] = (float)z;
+			((gmt_grdfloat *)vptr)[k] = z;
 			break;
 		case 'd':
 			((double *)vptr)[k] = (double)z;
diff --git a/src/gmt_gdalcall.c b/src/gmt_gdalcall.c
index edaeb235548..4ded757d614 100644
--- a/src/gmt_gdalcall.c
+++ b/src/gmt_gdalcall.c
@@ -193,9 +193,9 @@ GMT_LOCAL int save_grid_with_GMT(struct GMT_CTRL *GMT, GDALDatasetH hDstDS, stru
 		return -1;
 	}
 
-	if (nPixelSize != sizeof(float)) {		/* If outdata type is not 4 bytes, must create a tmp to copy from because GMT requires floats */
+	if (nPixelSize != sizeof(gmt_grdfloat)) {		/* If outdata type is not 4 bytes, must create a tmp to copy from because GMT requires floats */
 		size_t k;
-		if ((tmp = calloc(Grid->header->nm, sizeof(float))) == NULL) {
+		if ((tmp = calloc(Grid->header->nm, sizeof(gmt_grdfloat))) == NULL) {
 			GMT_Report (GMT->parent, GMT_MSG_ERROR, "grdgdal: failure to allocate temporary memory\n");
 			return -1;
 		}
@@ -205,7 +205,7 @@ GMT_LOCAL int save_grid_with_GMT(struct GMT_CTRL *GMT, GDALDatasetH hDstDS, stru
 			return -1;
 		}
 		for (k = 0; k < Grid->header->nm; k++)
-			Grid->data[k] = (float)tmp[k];
+			Grid->data[k] = (gmt_grdfloat)tmp[k];
 
 		free(tmp);
 	}
@@ -221,7 +221,7 @@ GMT_LOCAL int save_grid_with_GMT(struct GMT_CTRL *GMT, GDALDatasetH hDstDS, stru
    data comes upside-down as comparing to what it used to do. But since that in fact helps
    us since we no longer need to a flipud, we did not complain to GDAL dev. */
 #if (GDAL_VERSION_MAJOR < 3 && GDAL_VERSION_MINOR < 6)
-	gmt_grd_flip_vertical (Grid->data, (unsigned)nXSize, (unsigned)nYSize, 0, sizeof(float));
+	gmt_grd_flip_vertical (Grid->data, (unsigned)nXSize, (unsigned)nYSize, 0, sizeof(gmt_grdfloat));
 #endif
 
 	if (GMT_Write_Data (GMT->parent, GMT_IS_GRID, GMT_IS_FILE, GMT_IS_SURFACE, GMT_CONTAINER_AND_DATA,
diff --git a/src/gmt_grdio.c b/src/gmt_grdio.c
index 038256e9a4c..22ccd3dd3e8 100644
--- a/src/gmt_grdio.c
+++ b/src/gmt_grdio.c
@@ -1641,7 +1641,7 @@ size_t gmtlib_grd_data_size (struct GMT_CTRL *GMT, unsigned int format, gmt_grdf
 			return (sizeof (int32_t));
 			break;
 		case 'f':
-			return (sizeof (float));
+			return (sizeof (gmt_grdfloat));
 			break;
 		case 'd':
 			return (sizeof (double));
diff --git a/src/gmt_io.c b/src/gmt_io.c
index 04db3050702..aa9cd615850 100644
--- a/src/gmt_io.c
+++ b/src/gmt_io.c
@@ -1558,6 +1558,7 @@ GMT_LOCAL int gmtio_L_read_swab (struct GMT_CTRL *GMT, FILE *fp, uint64_t n, dou
 
 /*! . */
 GMT_LOCAL int gmtio_f_read (struct GMT_CTRL *GMT, FILE *fp, uint64_t n, double *d) {
+    /* Not gmt_grdfloat since applies to tables */
 	/* read float */
 	uint64_t i;
 	size_t k;
@@ -1845,6 +1846,7 @@ GMT_LOCAL int gmtio_L_write_swab (struct GMT_CTRL *GMT, FILE *fp, uint64_t n, do
 /*! . */
 GMT_LOCAL int gmtio_f_write (struct GMT_CTRL *GMT, FILE *fp, uint64_t n, double *d) {
 	/* write float */
+    /* Not gmt_grdfloat since applies to tables */
 	uint64_t i;
 	gmt_M_unused(GMT);
 	for (i = 0; i < n; ++i) {
diff --git a/src/gmt_map.c b/src/gmt_map.c
index ea9daf51821..da100629c74 100644
--- a/src/gmt_map.c
+++ b/src/gmt_map.c
@@ -8389,7 +8389,7 @@ int gmt_grd_project (struct GMT_CTRL *GMT, struct GMT_GRID *I, struct GMT_GRID *
 			struct GMT_GRID *G = NULL;
 			if ((G = GMT_Create_Data (GMT->parent, GMT_IS_GRID, GMT_IS_SURFACE, GMT_CONTAINER_AND_DATA, NULL, O->header->wesn, O->header->inc, \
 				O->header->registration, GMT_PAD_DEFAULT, NULL)) == NULL) goto bail_grd_dbg;
-			for (k = 0; k < G->header->size; k++) G->data[k] = (float)nz[k];
+			for (k = 0; k < G->header->size; k++) G->data[k] = (gmt_grdfloat)nz[k];
 			(void) GMT_Write_Data (GMT->parent, GMT_IS_GRID, GMT_IS_FILE, GMT_IS_SURFACE, GMT_CONTAINER_AND_DATA, NULL, "nz_grd_counter.grd", G);
 			GMT_Report (GMT->parent, GMT_MSG_NOTICE, "gmt_grd_project: Antialias counter nz written to grid file nz_grd_counter.grd\n");
 			GMT_Destroy_Data (GMT->parent, &G);
@@ -8618,7 +8618,7 @@ int gmt_img_project (struct GMT_CTRL *GMT, struct GMT_IMAGE *I, struct GMT_IMAGE
 			struct GMT_GRID *G = NULL;
 			if ((G = GMT_Create_Data (GMT->parent, GMT_IS_GRID, GMT_IS_SURFACE, GMT_CONTAINER_AND_DATA, NULL, O->header->wesn, O->header->inc, \
 				O->header->registration, GMT_PAD_DEFAULT, NULL)) == NULL) goto bail_img_dbg;
-			for (k = 0; k < G->header->size; k++) G->data[k] = (float)nz[k];
+			for (k = 0; k < G->header->size; k++) G->data[k] = (gmt_grdfloat)nz[k];
 			(void) GMT_Write_Data (GMT->parent, GMT_IS_GRID, GMT_IS_FILE, GMT_IS_SURFACE, GMT_CONTAINER_AND_DATA, NULL, "nz_img_counter.grd", G);
 			GMT_Report (GMT->parent, GMT_MSG_NOTICE, "gmt_grd_project: Antialias counter nz written to grid file nz_img_counter.grd\n");
 			GMT_Destroy_Data (GMT->parent, &G);
diff --git a/src/gmt_plot.c b/src/gmt_plot.c
index c5bc18c2e11..441ccaec081 100644
--- a/src/gmt_plot.c
+++ b/src/gmt_plot.c
@@ -10829,7 +10829,7 @@ struct GMT_POSTSCRIPT * gmt_get_postscript (struct GMT_CTRL *GMT) {
 	return (P);
 }
 
-void gmt_plot_image_graticules (struct GMT_CTRL *GMT, struct GMT_GRID *G, struct GMT_GRID *I, struct GMT_PALETTE *P, struct GMT_PEN *pen, bool skip, double *intensity) {
+void gmt_plot_image_graticules (struct GMT_CTRL *GMT, struct GMT_GRID *G, struct GMT_GRID *I, struct GMT_PALETTE *P, struct GMT_PEN *pen, bool skip, double *intensity, bool grdview) {
 	/* Lay down an image using polygons of the graticules.  This is recoded from grdview
 	 * so it can also be used in grdimage.
 	 * G is the data grid
@@ -10874,8 +10874,19 @@ void gmt_plot_image_graticules (struct GMT_CTRL *GMT, struct GMT_GRID *G, struct
 			gmt_illuminate (GMT, *intensity, fill.rgb);
 		n = gmt_graticule_path (GMT, &xx, &yy, 1, true, G->x[col] - inc2[GMT_X], G->x[col] + inc2[GMT_X], G->y[row] - inc2[GMT_Y], G->y[row] + inc2[GMT_Y]);
 		gmt_setfill (GMT, &fill, outline);
-		S->data[GMT_X] = xx;    S->data[GMT_Y] = yy;    S->n_rows = n;
-		gmt_geo_polygons (GMT, S);
+		if (GMT->current.proj.three_D && grdview) {	/* Deal with grdview */
+			uint64_t k;
+			double xp, yp;
+			for (k = 0; k < n; k++) {
+				gmt_geoz_to_xy (GMT, xx[k], yy[k], G->data[ij], &xp, &yp);
+				xx[k] = xp;	yy[k] = yp;
+			}
+			PSL_plotpolygon (GMT->PSL, xx, yy, n);
+		}
+		else {	/* 2-D, most likely grdimage w/wo -p */
+			S->data[GMT_X] = xx;    S->data[GMT_Y] = yy;    S->n_rows = n;
+			gmt_geo_polygons (GMT, S);
+		}
 		gmt_M_free (GMT, xx);
 		gmt_M_free (GMT, yy);
 	}
diff --git a/src/gmt_prototypes.h b/src/gmt_prototypes.h
index d1f92929145..395a5ea5479 100644
--- a/src/gmt_prototypes.h
+++ b/src/gmt_prototypes.h
@@ -272,7 +272,7 @@ EXTERN_MSC struct GMT_GRID * gmt_duplicate_grid (struct GMT_CTRL *GMT, struct GM
 
 EXTERN_MSC int gmt_two_curve_fill (struct GMT_CTRL *GMT, struct GMT_DATASEGMENT *S1, struct GMT_DATASEGMENT *S2, struct GMT_FILL *F1, struct GMT_FILL *F2, struct GMT_PEN *P1, struct GMT_PEN *P2, struct GMT_PEN *P3, char *sec_label);
 EXTERN_MSC void gmt_plot_timex_grid (struct GMT_CTRL *GMT, struct PSL_CTRL *PSL, double w, double e, double s, double n, unsigned int item);
-EXTERN_MSC void gmt_plot_image_graticules (struct GMT_CTRL *GMT, struct GMT_GRID *G, struct GMT_GRID *I, struct GMT_PALETTE *P, struct GMT_PEN *pen, bool skip, double *intensity);
+EXTERN_MSC void gmt_plot_image_graticules (struct GMT_CTRL *GMT, struct GMT_GRID *G, struct GMT_GRID *I, struct GMT_PALETTE *P, struct GMT_PEN *pen, bool skip, double *intensity, bool grdview);
 EXTERN_MSC double gmt_inch_to_degree_scale (struct GMT_CTRL *GMT, double lon0, double lat0, double azimuth);
 EXTERN_MSC bool gmt_text_is_latex (struct GMT_CTRL *GMT, const char *string);
 EXTERN_MSC void gmt_map_text (struct GMT_CTRL *GMT, double x, double y, struct GMT_FONT *font, char *label, double angle, int just, unsigned int form);
diff --git a/src/grdimage.c b/src/grdimage.c
index 474e26d14bf..29712cc8ce9 100644
--- a/src/grdimage.c
+++ b/src/grdimage.c
@@ -1709,7 +1709,7 @@ EXTERN_MSC int GMT_grdimage (void *V_API, int mode, void *args) {
 
 	if (Ctrl->T.active) {	/* Plot colored graticules instead */
 		need_to_project = false;	/* Since we are not doing reprojection of the grid */
-		gmt_plot_image_graticules (GMT, Grid_orig, Intens_orig, P, (Ctrl->T.outline) ? &Ctrl->T.pen : NULL, Ctrl->T.skip, Ctrl->I.constant ? &Ctrl->I.value : NULL);
+		gmt_plot_image_graticules (GMT, Grid_orig, Intens_orig, P, (Ctrl->T.outline) ? &Ctrl->T.pen : NULL, Ctrl->T.skip, Ctrl->I.constant ? &Ctrl->I.value : NULL, false);
 		goto basemap_and_free;	/* Skip all the image projection and just overlay basemap and free memory */
 	}
 
diff --git a/src/grdinterpolate.c b/src/grdinterpolate.c
index 901cceaea04..96e2df188da 100644
--- a/src/grdinterpolate.c
+++ b/src/grdinterpolate.c
@@ -746,7 +746,7 @@ EXTERN_MSC int GMT_grdinterpolate (void *V_API, int mode, void *args) {
 				So = Out->table[0]->segment[seg];	/* Short hand to this output segment */
 				for (row = 0; row < So->n_rows; row++) {
 					ij = gmt_M_ijp (Grid->header, So->n_rows-row-1, seg);	/* Must flip order since rows in grid goes down */
-					Grid->data[ij] = (float)So->data[3][row];
+					Grid->data[ij] = (gmt_grdfloat)So->data[3][row];
 				}
 			}
 			if (GMT_Destroy_Data (API, &Out) != GMT_OK) {
@@ -888,7 +888,7 @@ EXTERN_MSC int GMT_grdinterpolate (void *V_API, int mode, void *args) {
 				i_value[k] = C[GMT_IN]->data[node+k*C[GMT_IN]->header->size];
 			gmt_intpol (GMT, C[GMT_IN]->z, i_value, NULL, C[GMT_IN]->header->n_bands, n_layers, level, o_value, 0.0, int_mode);	/* Resample at requested output levels */
 			for (k = 0; k < n_layers; k++)	/* For all output levels, place the interpolated values at this (x,y) across all levels */
-				C[GMT_OUT]->data[node+k*C[GMT_OUT]->header->size] = (float)o_value[k];
+				C[GMT_OUT]->data[node+k*C[GMT_OUT]->header->size] = (gmt_grdfloat)o_value[k];
 		}
 	}
 	GMT_Destroy_Data (API, &C[GMT_IN]);	/* Done with the input cube */
diff --git a/src/grdview.c b/src/grdview.c
index 19f27164b30..2d2d952c475 100644
--- a/src/grdview.c
+++ b/src/grdview.c
@@ -1306,7 +1306,7 @@ EXTERN_MSC int GMT_grdview (void *V_API, int mode, void *args) {
 	}
 
 	if (Ctrl->T.active)	/* Plot colored graticules instead */
-		gmt_plot_image_graticules (GMT, Topo, Intens, P, (Ctrl->T.outline) ? &Ctrl->T.pen : NULL, Ctrl->T.skip, Ctrl->I.constant ? &Ctrl->I.value : NULL);
+		gmt_plot_image_graticules (GMT, Topo, Intens, P, (Ctrl->T.outline) ? &Ctrl->T.pen : NULL, Ctrl->T.skip, Ctrl->I.constant ? &Ctrl->I.value : NULL, true);
 	else if (Ctrl->Q.mode == GRDVIEW_IMAGE) {	/* Plot image */
 		int nx_i, ny_i, ip, jp, min_i, max_i, min_j, max_j, dist;
 		int done, layers, last_i, last_j;
diff --git a/src/testapi_gmtgrid.c b/src/testapi_gmtgrid.c
index fb48518fc56..8bcc74ac4a8 100644
--- a/src/testapi_gmtgrid.c
+++ b/src/testapi_gmtgrid.c
@@ -10,7 +10,7 @@ int main () {
 	uint64_t dim[2] = {5, 4};
 	char args[1000] = {""};
 	char input[GMT_VF_LEN] = {""};
-	float *data = NULL;
+	gmt_grdfloat *data = NULL;
 
 	API = GMT_Create_Session ("testapi_gmtgrid", 2U, mode, NULL);
 
@@ -18,8 +18,8 @@ int main () {
 	G = GMT_Create_Data (API, GMT_IS_GRID, GMT_IS_SURFACE, GMT_CONTAINER_ONLY, dim, NULL, NULL, 0, 2, NULL);
 
 	/* Allocate memory of the data array in the external program (C or PyGMT) */
-	data = (float *)malloc(sizeof(float) * 9 * 8);
-	for (int i = 0; i < 9 * 8; i++) data[i] = (float)i;
+	data = (gmt_grdfloat *)malloc(sizeof(gmt_grdfloat) * 9 * 8);
+	for (int i = 0; i < 9 * 8; i++) data[i] = (gmt_grdfloat)i;
 
 	/* Assign the user data to the GMT_GRID structure */
 	G->data = data;