The Dam Truck has always been a very suspicious object. It has been suggested that at one point it was to be blown up (there is 00E8 PchrdynamiteZ, right before 00E9 PchrbungeeZ).

I tend to think it was going to be used for more than just a way to know where you're going, and a bullet shield.

The Russian text here means "STOP" in English, but it probably was added at the end anyways.

What's also interesting is that the inside of the doors are textured. You cannot see this texture any other way, without the walk through the object code on, because it has very tinted black glass.

Perhaps they intended to place a guard inside like with Natalya?

It's likely the Russian Commandant found early in the level had some alternate purpose. There are only three commandants in the game: Dam, Surface, and Bunker.

The commandant in Surface holds a key, so it's again likely this one held a key, presumably to the boat.

Here's a close-up of going to the boat. Note that the actual Y coordinate of the boat may not be right, although it is estimated here, because the object here is actually a crate turned into a boat.

It is uncertain as to whether the game would go to cut-scene when Bond entered the boat, or would immediately take off.

It seems more likely that the boat would go around without a cut-scene, since not one other level has a mid-game cut-scene, and the turret and guards on the island may have fired at Bond.

This brings into question the speed of the boat. It probably would have travelled at a normal speed, a little faster than the Dam truck (it is called a speedboat in memory after all), stopped at the Dam, and waited for Bond to get out and then get back in.

Using a code to walk across the water, the following are the times it takes to get across:

Turbo: 25 seconds
Normal : 54 seconds
Guard Walking: 3 Mins 21 Seconds

Quite lengthy, so it is uncertain how it all would have worked. Perhaps Rare noticed the same length trek across the water, and saw that it took away from an introductory level that was otherwise linear and fast-paced.

The most likely objects that fit the presets laid out on the island are for Guards and their paths. Putting that into play, there are two guards pacing around the island: one on the tower, one on the ground. Perhaps Bond was supposed to pick off the guards with his sniper rifle during the trip on the boat.

The guards pace around in similar ways to the other guards in the level, and do seem appropriate.

The turret is only a wall texture, which means they probably had not made them at this point in construction of the game, and it is only a placeholder.

At this point in development, they may not have decided how Bond was to destroy the turret. Bullets may have been utilized unless they intended to arm Bond with a rocket launcher or grenade.

Like the other towers, Bond could climb the ladder and go upstairs. Because of the alignment of the tower, it's quite possible there was something to be collected.

Probably nothing, but I really could see some sort of vehicle sitting here. The little yellow warning strip seems to indicate that, and this room is pretty far off in the Dam.

Just suspicious, but not necessarily anything, I don't think the Dam truck would've traversed the entire Dam, because it'd block your path, but possible.

The end grate for the level, which is unviewable without using the level never ends code.

This has to be tied in to the piton gun. It seems highly likely that the same train pieces that are shot off to drop that trapdoor would drop here as well.

Although the white plate is missing here, you probably would have to destroy something like the train brakes.

Instead of the watch laser, you would use the piton gun.

The piton gun in Goldeneye was equipped with a laser, in which Bond cut through the Dam grate to get into facility.

In Dam, had the whole ending been as they had originally thought, Bond would most likely bungee down, and then cut through the grate, finally ending the level and going to cut-scene.

Complicated to do, probably complicated to program, and they probably realized did not fit the games whole feel as well.

None of these gadgets remain: all replaced by a default grenade weapon.

The bungee was undoubtably for Dam, as it is the only level where bond Bungees off, and is in fact even an objective.

Currently, Bond merely has to walk off the Dam to complete this objective. In the beta version screenshots, this objective was always complete to start the level, indicating it was never implemented.

Perhaps a simple bungee was to be done, not anything horrible like MI for N64, but this also did not fit the difficulty for the first level of the game or the game itself.