Natural Obstacles and Hazards
Tropical Ground
           Generally, the tropical ground is more stable than alpine ground with its volatile snow/ice conditions. Occurring often during a torrential rain or typhoon after a long period of drought, a landslide or rockslide is by far less frequent than alpine avalanches. In terms of footing, tropical ground is more stable than either ice or snow. As such, in tropical slopes equivalent to alpine Grade II and III, the recommended use of crampons and roping technique is practically irrelevant.

Type and Angle of Slope
          
Face/Wall (Technical Slope): Usually referring to rocks, it refers to slopes equivalent to Grade IV to VII that requires the use of belay-lead climbing. Generally, the scale of rock-faces in the country is not suited for big-wall climbing. A case in point, Mt Manaphag has rocky mountainsides yet these are formed by a terrace of big rock boulders separated in-between by broad ledges with a forest cover. At any rate, belay-lead climbing, whether free climbing or direct-aid climbing, is the most hazardous method of climbing. Moreover, risk, particularly risk of a fall, is multiplied when protection is abandoned.
            Significantly, the country has a share of sheer mountainsides that are not made of solid rocks. They have vegetative cover and the steepest sections could only host the growth of small ferns. Belay-lead climbing for this type of slope requires the use of special equipment to purchase a hold and anchors similar to an ice-screw in ice/alpine climbing.
          
Non-Technical Slopes: Referring to slopes gentle enough to disregard belay-lead climbing, the Non-Technical Slope is relatively the safest and easiest to climb. At any rate, much of the stress is concentrated in the lower limbs. Strain of load affecting much of shoulder and back muscles is felt much in uphill climb than in the downhill climb. The increase in load-weight has a commensurate increase in strain. The strain of load is heightened as angle increases, particularly in the uphill climb.
          
Walk-Up Slope: A non-technical slope, it could be climbed with the occasional use of hands. The least strenuous climb is a walk-up yet sustained climb on such slope, say for two or more hours, could be exhausting. This happens because stress has been prolonged and concentrated in a few lower limb muscles. (Walk-up over a slope with varied angles and constant variation of uphill and downhill climb may prove less stressful.)
          
Scrambling Slope: A non-technical slope, it requires the frequent use of hands for balance and pull-ups. Scrambling is facilitated by handholds, mostly from parts of plants, and hindered by slippage. The strain of load is increased and the shoulder/back muscles took the brunt of much stress. The equivalent of alpine Grade II and III, this slope nonetheless does not require roping and the use of crampons as in alpine climbing.

Terrain
          
Ridge: Exposure is the dominant element of the ridge. Exposed positions such as a narrow crest, at times only a foot in width, maximizes potential for a fall. In some instance, exposure appears as a tight passageway across the edge of a ridge. While tropical ground is generally stable, several factors could contribute to a fall aside from loose rocks, slick rocks and deceptively strong footing. Among these factors are fatigue and misjudgment of footing.  For extra protection and for a psychological boost, roping or the fixing of a line may be utilized on a ridge.
           A rock-boulder is a natural obstacle on ridges. Some of these boulders rises to as high as 20 ft and may need a modicum of technical climbing.
           On the upside, a ridge affords an ideal position for perspective viewing. On the downside, the presence of water and adequate tent ground is scarce, if not totally absent, on ridges.
          
Ravine (Valley or Canyon): Commonly accepted to provide a reliable course down a mountain, the bottom of two elevations actually provides a very limited perspective.
           A waterfall is a natural obstacle on a ravine. Some waterfalls, some a thousand feet tall, requires expertise in abseiling or technical climbing. A natural hazard, the rocks on a ravine could be slick from moss or water and cause slippage that may result into a fracture – a very grave concern in the outback.
           On the upside, the bottom of a ravine likely has water – the most dominant factor in tropical climbing. On the downside, the watercourse is the convergent point of most harmful biological organisms – snakes, wild pig (aggressive when cornered), disease-carrying mosquitoes, bacteria, etc. In addition, the declivity receives the brunt of rockslides, landslides and flashfloods. The latter accounts as the leading cause of fatality in Philippine Mountaineering.

Vegetative Obstacles
          In alpine climbing, a deep snow requires a slow and laborious slogging. An impediment, a snow is much like vegetation in tropical climbing.
         
Forest:  While there are many types of forest, the major concern in movement across a forest is the presence of undergrowth as the real impediment. Understandably, the degree of undergrowth density requires a commensurate amount of labor for hacking or clearing. Notably, the thorns like uway and salimao need not be dense to pester smooth progress.
          On the upside, the forest canopy provides a shelter from the heat of the sun and it is a source of edible plants and animals. On the downside, the forest is the habitat of many harmful biological organisms and the canopy is an obstruction for perspective viewing.
        
Scrub: The scrub thrives on a terrain less able to retain water like the sheer summit-wall and the ridge. Almost impassable, a growth of scrub is normally dense. The lower elevation of a high elevation offsets the heat of the sun in a virtually open scrubland.
         
Bariw: Belonging to the pandan-family, the bariw has unique impediment qualities. Its spiny stalks like that of a pineapple could inflict bruises and its intertwining branches resist passage. While it normally grows on the summit-wall, it grows in profusion on ridges. Disregarding hacking of branches to clear a way through a bariw growth, warding off branches is a laborious task. The most exhausting passage could be had on a bariw-covered ridge without any existing trail. The classic example of a bariw ridge is the Bakiras Ridge of Sewahon Peak (Sicaba-Daku). The first traverse along the 3km span of Bakiras Ridge was done in 1˝ days.
         
Salindugok: A creeper-fern, a salindugok thrives on spots of cleared forest. With hacking rendered ineffective in clearing a way through a salindugok growth, the most efficient method is ‘foot-trashing’ – raising the feet high enough to step on the dense growth and pressing it to the ground. However, while ‘foot-trashing’ is effective on a level ground, it becomes impracticable on a steep incline. On the latter case, the hands and even the torso could be used for pressing the growth to the ground. In consolation, a salindugok does not grow as extensively as the scrub or the bariw.
          
Cogon: The cogon the most resilient grass able to grow on slopes cleared by logging. The lower west slopes of Antique mountains are the classic example of cogonal slopes. Even with the relative ease provided by an extant trail along a cogonal slope, movement across it under the sweltering heat of the sun is almost unbearable. Moreover, the wet ground of a cogonal trail is very slippery when wet.
           On the upside, perspective viewing on a cogonal slope is excellent, minus other obstructions.

Existence/Absence of Trail
           Understandably, the presence of an established trail minimizes in a relative degree the impediment of vegetation. Of course, an extant trail may either be slightly used (conditionally overran by growth) or overused (relatively clear).
           Trail types include a logging road and a foot-trail. Broader, a logging road doesn’t have the steepness of some foot-trail sections. Usually the handiwork of a ‘mangunguway’ (rattan-gatherer), a foot-trail may take the form of a saugan – a trail worn by carabao-drawn sled. Sometimes, a worn-out saugan is as deep as twenty feet. It is very slippery when wet.
Weather Conditions
          There are only two pronounced seasons in the Philippines – the wet season (rainy) and the dry season (summer).
         
Dry Climb: Preferred by the majority of Filipino mountaineers, a Dry Climb takes advantage of the less slippery trail and the absence of a muddy campground. On the downside, climbing in cogonal or open sections could be very exhausting.
         
Wet Climb: Opposite of the Dry Climb, a Wet Climb is marred by slippery trail, muddy campground, high exposure to water and abundance of the blood-sucking limatik or alimatok. In a Wet Climb, period for movement is shortened as time devoted for fixing and breaking of camp is lengthened. Most significantly, almost all cases of hypothermia and flashflood in Philippine Mountaineering occurred during the wet season – also the period of tropical storms and typhoons.
          On the upside, hike or climb rate even in open places in increased with the relatively low temperature. Of course, the rain is a source of potable water. Availability of rainwater could save the life of a climber who is stranded on a high ridge. (Significantly, dehydration causes tardiness and poor judgment – the silent factors for the supposedly improbable accidental fall in the relatively stable ground of tropical mountains.)

Water-Sourcing
           Ironically, water supply is a dominant factor for either the success or failure of a tropical climb. Reportedly, the Antique Mountaineering Society failed to climb Mt Nangtud through the Valderrama trail in two attempts because of water shortage.
           In alpine climbing, the amount of water supply depends on the amount of fuel for thawing ice into water. In tropical climbing, the amount of water supply directly depends on the distance of the nearest water-source (a spring or creek) and the capacity of a climber to carry a certain load.
          Naturally, the absence of a water-source for a relative period determines the difficulty of water-sourcing. 
Orientation Problems
          While the effects of altitude play a very important part in alpine climbing, tropical climbing is dominated by orientation problems (provided a mountain guide is out of the picture). Visual obstructions such as the terrain, forest and fog contribute to make orienteering very difficult. All other obstructions have already been detailed except for the fog. A gaseous emission of trees, a fog occurs frequently and thickly in densely forested mountains. A dense fog is, firstly,  the most effective visual obstruction. Secondly, it poses a serious threat to life. Prolonged presence of fog may detain a climber to a spot for a critical period – complicated possibly by shortening of supplies or exposure to cold. Of course, movement under zero-visibility is ill-advised. A few deaths from accidental fall in Mt Kanla-on have been attributed to movement under zero-visibility in the fog.
          Disorientation causes delay in hours or even days. Getting stranded in the outback beyond the limit of supplies results to several imaginable consequences – including death.

Tropical Hazards
          Tropical hazards like flashflood, rockslide, landslide, typhoon or storm, biological organisms and the `natural obstacles’ are phenomena of nature. They are the indirect cause of health hazards, common to mountaineering, such as drowning, hypothermia, dehydration, nutritional deficiency, poisoning, bacterial infection and soft tissue or musculo-skeletal injuries.
           Further attempt to explain each of these is considered unnecessary because, for one, at least each has already been mentioned or explained previously to some degree. At any rate, the following hazards need further elucidation and others special mention:
          
Volcanic Eruption/Explosion: Practically, any mountaineering venture is temporarily halted in a volcanic mountain in the brink or in the process of explosion or eruption. The PHIVOLCS doing the round-the-clock monitoring of active volcanoes in the Philippines issues such advisory or warning for the cancellation of climbs. However, despite of the existing safety measures, a volcano may erupt without warning. Such sudden explosion happened on August 10, 1996 that killed a Briton and a Filipino mountaineer in Mt Kanla-on, one of the most active volcanoes in the country.
          
Human Conflict /Insurgency: In truth, the mountaineers are not the direct target of the insurgents – NPAs, RPAs, MILFs, etc. – that take refuge in the boondocks around the country. However, despite of their non-combatant status, they are pitted there as potential recipients of the culture of violence and suspicion perpetrated by the long-drawn military-rebel conflict. From experience, even the military is a source of such threat of violence, particularly out of suspicion of mountaineer’s complicity with the rebels. Historically, cases of detention of mountaineers from the hands of both the military and rebels had happened in Negros, Panay, Mindanao and other parts of the country. 
          
Flashflood: The leading cause of fatality in Philippine Mountaineering, a flashflood could happen so fast before any mitigation measure – the speedy abandonment of the declivity – could be carried out. The death of three mountaineers from flashflood in Mt Guiting-Guiting was due in part to wrong judgment – camping in the river. Others had been killed while crossing a fast-rising flood. Meanwhile, an almost dry river-bed in Mt Kanla-on suddenly rose to a torrent wiping a band of unsuspecting mountaineers. (Dubbed as a ‘killer-mountain’, Mt Kanla-on has killed a lot from all sorts of causes – accidental fall in zero-visibility fog, fall after slipping on the rock on a ridge, hypothermia, flashflood, etc. Allegedly, a German Everester is among the several victims of Mt Kanla-on.)
          
Hypothermia: The second leading cause of mountaineering fatality in the country, hypothermia is a potential hazard during a typhoon or storm. Actually, hypothermia is caused by the lowering of body temperature. Although sub-zero temperature is a rare occurrence in Philippine mountains (the worst is minus-two degrees Centigrade), there are secondary factors contributing to the lowering of body temperature aside from the prevailing temperature level of the environment. These are the wind chill, water exposure and inadequate clothing (lack of muscular activity may be added). Except for the last, they are prevalent during a typhoon or storm. All three secondary factors contributed to the death from hypothermia of three mountaineers in Mt Halcon in 1999.
Mountaineering in the Philippines