Scuba Tanks

Aluminum vs. steel — the core decision
Aluminum tanks are corrosion-resistant, less expensive, and the most widely available for rental worldwide — the aluminum 80 cubic foot is the standard North American dive tank. The trade-off is buoyancy: aluminum tanks become positively buoyant as gas is consumed, which most divers compensate for with extra lead weight. Steel tanks are stronger, allowing thinner walls and a more compact cylinder for equivalent volume. They remain negatively buoyant throughout the dive, which can eliminate or significantly reduce the need for weight belt ballast — a meaningful advantage for drysuit divers in Canadian cold water who already carry considerable weight.

Capacity — match it to your diving
Tank capacity is expressed in cubic feet (imperial) or litres (metric). The aluminum 80 cubic foot (approximately 11 litres at 200 bar) is the standard recreational tank and the right starting point for most divers. Smaller cylinders — 63 to 72 cubic feet — suit junior divers and shallow reef diving. Larger steel cylinders of 95 to 120 cubic feet provide extended bottom time for cold-water divers with higher gas consumption, technical divers, and drysuit divers whose breathing rate tends to run higher due to thermal stress. Pony bottles of 6 to 30 cubic feet provide an independent emergency gas supply for more demanding diving.

Canadian tank inspection requirements
Under Transport Canada regulations, all compressed gas cylinders used for diving in Canada must have a current annual visual inspection (VIP) and a hydrostatic pressure test every five years. A VIP involves a certified inspector examining the interior and exterior for corrosion, pitting, damage, and contamination. A hydrostatic test verifies the structural integrity of the cylinder under test pressure. A tank out of date on either inspection cannot legally be filled at any dive shop in Canada. When purchasing a tank — new or used — confirm the most recent hydrostatic test date stamped on the neck and ensure a current annual VIP sticker is present.

Own vs. rent
Most recreational divers who travel for diving rent tanks at their destination — transporting cylinders by air is complicated, expensive, and impractical on international travel. Owning your own tank makes the most sense for divers who dive locally and frequently in Canada, particularly in areas where rental availability is limited or where steel tank buoyancy properties provide a meaningful weight system advantage. If you dive mostly on guided trips to tropical destinations, renting is the simpler approach. If you dive locally within Canada regularly, ownership offers convenience and the ability to choose your cylinder configuration.