We have just completed the Otter Trail.
I think it is important to give a little inf on the Bloukraans river crossing.
Since the floods a few years ago the mouth at the Bloukraans has changed dramatically. ALL the sand has been washed from the mouth, and the river bed is now smooth pebbles and rocks. The floods have scoured out the river and it is now impossible to walk across. If you wish to cross you WILL HAVE TO SWIM, with your bags, across the river. The decision you face when reaching the river is quite tough. There are many options, depending on your ability, equipment and the local conditions.
The map you will be issued with as you depart will explain, with a diagram your options.
You have 3 basic options:
Option A:
A long swim (about 60m) though the swell (or breakers depending on the daily conditions). The exit here is easier, and allows a walk out of the sea (after negotiating a few submerged boulders through the breaking waves), into a sandy channel. From there, access to the trail is staight forward.
Option B:
Here the swim is further up river. The swim is shorter and depending where you exit, the swell size is much smaller. The exit here is much more difficult, requiring you to climb out onto a near vertical rock face. Remember you will have your backpacks in waterproof bags at this stage. Once you are out, there will be rock climbing (or "bouldering") to reach the path. The shorter the swim (about 20m minimum) the more climbing you will have to do.
Option C:
Take the STEEP escape route. Some people seem to regret this, thinking that the swim would be easier!
We had 50m of rope, and waterproof bags and easy clip off carabinas. We did the Option A swim. Our 50m rope did not reach from bank to bank and we held the free end in waist deep water, having to jump over swell as they rolled in. We were only 4 persons walking the trail and swam two bags at a time across the river, swimming the rope back to collect the second set of bags. All in all it went well, only small amounts of water wetting the outside of some backpacks. Mine was bone dry.
If you are considering the long swim, I would recommend:
1) Waterproof bags for your backpacks.
A survival bag may work but we were fortunate to get purpose built bags from the UK. We had 3 lightweight bags (waterproof, roll down with a clip to secure), one heavy duty one (the roll down sort, made of heavy plastic canvass). The bags were fantastic. When used properly they worked perfectly, trapping air with the backpack, helping to float the bags across. One has to be careful with any bag one it has the backpack in it, as one of ours got small rips in it from being placed on a rock. Check your bag just prior to the swim.
2) Duct tape. (lots of it)
Seal survival bags (fold down many times, then a strip of duct tape. Repeat). Fix holes in bags prior to the swim.
3) Rope.
If you want to do it comfortably, at least 75m of rope. (Perhaps in two or three lenghts?). Preferably
floating rope. Ours sank, snagging every now and then. It was easy to pull the air filled bags across, with two people swimming with the bags.
(Great rope shop near "The Spotty Dog" in Cape Town)
4) Carabinas or clips.
When exiting, you are buffeted by the waves, (with underwater rocks) and being able to quickly release bags makes a big difference. (we got away with minor scratches!)
5) Shoes you can swim in.
(And wear around camp after a long day's walk)
Slops tend to come off. The ideal would be those aqua shoes, wetsuit booties or well protected sandals (one of our party got quite badly cut though the opening in his sandals. Not great when you still have to walk). I had tight fitting crocs, which worked OK. Others ended up duct taping their shoes on.
6) Heavy duty garbage bags.
Put the backpack in the garbage bag first, duct tape it closed. Put that in the waterproof bag. "Belt and braces".
7) Ziploc Bags.
Put everything into one. "Belt and braces".
I found a "plastic" shop in Cape Town (next to the Engen Garage on Landsdowne Road near Access Park) that sold all shapes and sizes. Large ones are particularly useful. Take spares.
8 ) Plasters and antibacterial cream! (Fucidin)
Hope that helps! Being prepared helped us a lot. Hopefully the sand will all come back one day and walking across the river may become possible.
Just a note on the Lottering crossing. Get into swimming gear and have a walk through the river before trying with the pack. We swam our packs over, not knowing they could have been balanced on our head and walked over.