diff --git a/src/cressi_goa_parser.c b/src/cressi_goa_parser.c
index 579d662..35312db 100644
--- a/src/cressi_goa_parser.c
+++ b/src/cressi_goa_parser.c
@@ -28,9 +28,16 @@
 
 #define ISINSTANCE(parser) dc_device_isinstance((parser), &cressi_goa_parser_vtable)
 
-#define SZ_HEADER 0x61
+#define C_ARRAY_SIZE(array) (sizeof (array) / sizeof *(array))
+
+#define SZ_HEADER          23
+#define SZ_HEADER_SCUBA    0x61
+#define SZ_HEADER_FREEDIVE 0x2B
+#define SZ_HEADER_GAUGE    0x2D
 
 #define DEPTH       0
+#define DEPTH2      1
+#define TIME        2
 #define TEMPERATURE 3
 
 #define SCUBA       0
@@ -63,6 +70,13 @@ static const dc_parser_vtable_t cressi_goa_parser_vtable = {
 	NULL /* destroy */
 };
 
+static const unsigned int headersizes[] = {
+	SZ_HEADER_SCUBA,
+	SZ_HEADER_SCUBA,
+	SZ_HEADER_FREEDIVE,
+	SZ_HEADER_GAUGE,
+};
+
 dc_status_t
 cressi_goa_parser_create (dc_parser_t **out, dc_context_t *context, unsigned int model)
 {
@@ -102,7 +116,19 @@ cressi_goa_parser_set_data (dc_parser_t *abstract, const unsigned char *data, un
 static dc_status_t
 cressi_goa_parser_get_datetime (dc_parser_t *abstract, dc_datetime_t *datetime)
 {
-	if (abstract->size < SZ_HEADER)
+	const unsigned char *data = abstract->data;
+	unsigned int size = abstract->size;
+
+	if (size < SZ_HEADER)
+		return DC_STATUS_DATAFORMAT;
+
+	unsigned int divemode = data[2];
+	if (divemode >= C_ARRAY_SIZE(headersizes)) {
+		return DC_STATUS_DATAFORMAT;
+	}
+
+	unsigned int headersize = headersizes[divemode];
+	if (size < headersize)
 		return DC_STATUS_DATAFORMAT;
 
 	const unsigned char *p = abstract->data + 0x11;
@@ -125,11 +151,19 @@ cressi_goa_parser_get_field (dc_parser_t *abstract, dc_field_type_t type, unsign
 {
 	cressi_goa_parser_t *parser = (cressi_goa_parser_t *) abstract;
 	const unsigned char *data = abstract->data;
+	unsigned int size = abstract->size;
 
-	if (abstract->size < SZ_HEADER)
+	if (size < SZ_HEADER)
 		return DC_STATUS_DATAFORMAT;
 
 	unsigned int divemode = data[2];
+	if (divemode >= C_ARRAY_SIZE(headersizes)) {
+		return DC_STATUS_DATAFORMAT;
+	}
+
+	unsigned int headersize = headersizes[divemode];
+	if (size < headersize)
+		return DC_STATUS_DATAFORMAT;
 
 	if (!parser->cached) {
 		sample_statistics_t statistics = SAMPLE_STATISTICS_INITIALIZER;
@@ -153,7 +187,7 @@ cressi_goa_parser_get_field (dc_parser_t *abstract, dc_field_type_t type, unsign
 			*((double *) value) = parser->maxdepth;
 			break;
 		case DC_FIELD_GASMIX_COUNT:
-			*((unsigned int *) value) = 2;
+			*((unsigned int *) value) = divemode == SCUBA || divemode == NITROX ? 2 : 0;
 			break;
 		case DC_FIELD_GASMIX:
 			gasmix->helium = 0.0;
@@ -190,12 +224,28 @@ cressi_goa_parser_samples_foreach (dc_parser_t *abstract, dc_sample_callback_t c
 	const unsigned char *data = abstract->data;
 	unsigned int size = abstract->size;
 
-	unsigned int time = 0;
-	unsigned int interval = 5;
-	unsigned int complete = 1;
-	unsigned int gasmix_previous = 0xFFFFFFFF;
+	if (size < SZ_HEADER)
+		return DC_STATUS_DATAFORMAT;
 
-	unsigned int offset = SZ_HEADER;
+	unsigned int divemode = data[2];
+	if (divemode >= C_ARRAY_SIZE(headersizes)) {
+		return DC_STATUS_DATAFORMAT;
+	}
+
+	unsigned int headersize = headersizes[divemode];
+	if (size < headersize)
+		return DC_STATUS_DATAFORMAT;
+
+	unsigned int interval = divemode == FREEDIVE ? 2 : 5;
+
+	unsigned int time = 0;
+	unsigned int depth = 0;
+	unsigned int gasmix = 0, gasmix_previous = 0xFFFFFFFF;
+	unsigned int temperature = 0;
+	unsigned int have_temperature = 0;
+	unsigned int complete = 0;
+
+	unsigned int offset = headersize;
 	while (offset + 2 <= size) {
 		dc_sample_value_t sample = {0};
 
@@ -204,35 +254,44 @@ cressi_goa_parser_samples_foreach (dc_parser_t *abstract, dc_sample_callback_t c
 		unsigned int type  = (raw & 0x0003);
 		unsigned int value = (raw & 0xFFFC) >> 2;
 
-		if (complete) {
-			// Time (seconds).
+		if (type == DEPTH || type == DEPTH2) {
+			depth =  (value & 0x07FF);
+			gasmix = (value & 0x0800) >> 11;
 			time += interval;
-			sample.time = time;
-			if (callback) callback (DC_SAMPLE_TIME, sample, userdata);
-			complete = 0;
+			complete = 1;
+		} else if (type == TEMPERATURE) {
+			temperature = value;
+			have_temperature = 1;
+		} else if (type == TIME) {
+			time += value;
 		}
 
-		if (type == DEPTH) {
+		if (complete) {
+			// Time (seconds).
+			sample.time = time;
+			if (callback) callback (DC_SAMPLE_TIME, sample, userdata);
+
+			// Temperature (1/10 °C).
+			if (have_temperature) {
+				sample.temperature = temperature / 10.0;
+				if (callback) callback (DC_SAMPLE_TEMPERATURE, sample, userdata);
+				have_temperature = 0;
+			}
+
 			// Depth (1/10 m).
-			unsigned int depth = value & 0x07FF;
 			sample.depth = depth / 10.0;
 			if (callback) callback (DC_SAMPLE_DEPTH, sample, userdata);
 
-			// Gas change.
-			unsigned int gasmix = (value & 0x0800) >> 11;
-			if (gasmix != gasmix_previous) {
-				sample.gasmix = gasmix;
-				if (callback) callback (DC_SAMPLE_GASMIX, sample, userdata);
-				gasmix_previous = gasmix;
+			// Gas change
+			if (divemode == SCUBA || divemode == NITROX) {
+				if (gasmix != gasmix_previous) {
+					sample.gasmix = gasmix;
+					if (callback) callback (DC_SAMPLE_GASMIX, sample, userdata);
+					gasmix_previous = gasmix;
+				}
 			}
 
-			complete = 1;
-		} else if (type == TEMPERATURE) {
-			// Temperature (1/10 °C).
-			sample.temperature = value / 10.0;
-			if (callback) callback (DC_SAMPLE_TEMPERATURE, sample, userdata);
-		} else {
-			WARNING(abstract->context, "Unknown sample type %u.", type);
+			complete = 0;
 		}
 
 		offset += 2;